Author Topic: TC1 lcr-meter transistor-tester fix (Read 190676 times)

zappenduster · « **on:** June 21, 2018, 07:38:36 pm »

Hello eevblog forum,
here is my TC1 (TC-V2.12k) experience. If your tc1 doesn't switch on anymore check capacitor C11 and C12.

I got the meter two weeks ago (18 Euro ebay purchase, shipped from china to germany).
I tested about 20 components successfully and then: screen black. I no longer could turn it on.
It was not my fault - i surely did not connect a charged capacitor or external voltage to input terminals.
Only usb-charging function seemed still be OK: red LED for some time, then turned green.

U5 boost-IC of my flawed meter was getting hot; voltage at Cathode of D2 about 15V.
With some web-hints i figured out a faulty component: a short circuited C (C11 or C12 - not sure anymore which one; they are connected in parallel).
One of them got a 'short' of 120 Ohm. The other's value is 5uF. I replaced both with 100nF and 4,7uF electrolytic 100V-rating. Now the meter works again.
Cathode of D2 is now at 37V (47V during usb-charging). This voltage is generated for zener-diode testing.

While pcb-inspection i measured some capacitors: C8 = C9 = C14 = C15 = 9 uF. C10 = 118 nF
D1 = D2 = D3 = 'SL' marked diodes (schottky-type because U_f ~ 250mV).
U1 = 44-pin uC Atmega 324PA ; Y = 16MHz crystal
U4 = 8-pin uC STC15L104W for wake-up from sleep / measurement cycle / subsequent automatic power-off
U5 = 6-pin boost/step-up IC. Marking AL718 (another forum-post states AL605)
U6 = 6-pin charge-IC
ZD1 = zener-diode 6V8 ; DZ2 6-pin marked V05. Some pcb miss those two elements - maybe earlier layouts...
battery = li-ion 3.7V 450mAh ; some tc1 got a much larger battery (2x base area)

At this position there would be a picture of my handmade pcb-to-schematic translation together with the actual pcb - but i can't insert them here... You can find them attached at the end of this post.

Current consumption is 300..400 mA (On-state) and 0,2mA in Standby/power-off). That means 150mAh per month (0,2mA * 24h * 31 days). So a fully charged battery would be drained after three months of non-use.
While measuring the circuit sometimes this happened: Standby current 0,2mA switched to 10mA for 25 seconds. Then it sank to 15 uA and remained there till next (On-)Button pressing.
After some trial and error i ended up adding a 33k resistor to the 5V-regulator output (soldered piggyback onto C15). This seems to do the job of triggering the 10mA_for_25s period immediately after shutdown. By that sleep-mode is reached safely.

Operational states (duration/current): 25s -> 25s -> sleep
25 seconds: On-button was pressed, screen is lit, meter tries to identify connected component. I = 300..400 mA
25 seconds: 10 mA current draw after automatic shotdown, screen black
xx seconds: 15 uA sleep-mode till next button pressing / measurement cycle
If i keep my tc1 busy (pressing button repeatedly) sometimes the sequence is 170s-170s-sleep. I don't know what goes on here...

IR remot control detection:
The ir-indicator (red dot in upper-right corner of screen) is flickering sometimes although input-area is covered up. I added a 100nF capacitor between Ground and Vcc of ir-receiver. But no change, this intermittend behavior is still there...

My guess about U4 port-configuration: Pin_1 is configured as interrupt: pressing button wakes device from sleep. Pin_3 switches on U5 boost-ic. Pin 5+6 used as common input to determine desired automatic power-off time (10s/15s/20s/25s - depending on connections P1/P2 <-> Ground/U4_Vcc).
About U4 functionality see also https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1553608/#msg1553608

TC1 manual: www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=310740
TC1 high-resolution pictures: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/2225/
TC1 review + hr-pics: https://lygte-info.dk/review/ComponentTester%20Multifunction%20Tester%20T1%20UK.html
uC STC15L104W is described/listed here: http://www.stcmcu.com/datasheet/stc/STC-AD-PDF/STC15-English.pdf

Some web search brings up T6 labeled models (monochrome display, ir-receiver is placed on screen's right side). T7 looks the same as tc1. At startup it shows a brand/firmware name for a second.

Indicated data of tc1-testet components:
As lygte-info.dk review states, scr/triacs are partly recognised as resistor or BJT; h_FE values of darlington-transistors with BE-resistors are much too low.
To me also capacitor ESR-values seem low: My Peaktech 2063 LCR-meter shows much higher values (it's presumably identical to Extech 380193 meter; component test-frequency can be switched from 120Hz to 1kHz)
What do you think of those misrepresentations/discrepancies? Can i just add a fixed offset to displayed capacitor ESR-values?

Thank you to eevblog and previous contributors to that matter...
zappenduster

hydroksyde · « **Reply #1 on:** June 23, 2018, 04:47:04 am »

Thanks, mine just arrived with the same issue. Replacing C12 with a 100nF ceramic fixed the problem..

zmaxpayne · « **Reply #2 on:** June 29, 2018, 05:26:13 pm »

Hi to all.
I damaged mine (tc1).
I was so stupid to hook on a charged capacitor :-(.
So when i press to measure it stays black. Black screen.
The loading led is still working.
Do you guys think i can fix it?
What component could i damaged?
Thx.
Stefan from Belgium.

indman · « **Reply #3 on:** July 01, 2018, 12:31:48 pm »

Remove DZ1 = with zener-diode 6V8; DZ2 6-pin marked V05. To give power on a tester without remote elements. If the problem remains, then YOU have damaged the ATMega324 processor. His replacement and a new firmware is necessary.

cataboier · « **Reply #4 on:** July 09, 2018, 08:17:13 am »

Thanks so much !

ahmad_hodrob · « **Reply #5 on:** August 11, 2018, 08:29:21 am »

dear Sir,

kindly note that I have T7 transistor tester that suddenly stopped working upon checking i found that C11 is shorted I replaced it with a 10uf capacitor, know the device is working but it doesn't go to calibration mode when I connect a short wires to it, instead it reads the short wires as a resistors with a value of about 11 Mohm.

please I need an advice and if anybody can help me with the software of the unit.

flodo · « **Reply #6 on:** September 11, 2018, 10:10:47 am »

I made a new firmware for U4 and the standard-firmware

how to flash it is explained here and here

the current version is v0.2, you can find it here

Unfortunately my tc1 is still drawing 0.11mA at sleep mode - seems to be a bit high.
I am not yet sure what the problem is.

flodo · « **Reply #7 on:** September 11, 2018, 01:25:54 pm »

@zappenduster: how have you measured the drawn current? I wasn't able to do that properly since every resitance in series is preventing power on somehow.

Bighouse · « **Reply #8 on:** September 12, 2018, 07:51:55 pm »

My TC-1 suddenly only measures a weird cell voltage all the time. Whatever I put in the the thing. Shorting the 3 probe pins also doesn't trigger the autocalibration anymore

. Kind of a noob in this diagnosing. I don't read anyone having this specific problem.

The value varies somewhat, but it's between those pins all the time.

Any thoughts?

flodo · « **Reply #9 on:** September 14, 2018, 10:44:21 am »

Maybe this helps (thanks to indman for the schematic).
I would start by measuring all those components within the yellow marking (especially DZ2).

flodo · « **Reply #10 on:** September 14, 2018, 02:40:35 pm »

DZ2 is probably the most promising part since you seem to have a positive voltage at socket ② - is the diode still working correctly?
You can find a datasheet here: https://www.semtech.com/uploads/documents/srv05-4.pdf

You can get a new one here (at least in Germany): https://www.conrad.de/de/tvs-diode-bourns-cdsot23-srv05-4-sot-23-6-6-v-500-w-1055462.html

Bighouse · « **Reply #11 on:** September 17, 2018, 10:48:38 am »

I remember having the device plugged in with an (empty) Capacitor for a maybe a few weeks. Could it be that the capacitor got charged up by having it plugged in, and then releasing it's charge damaging my device in the process? I only hear about 'real' dead devices, with black screens when people plug in a charged capacitor. My issue looks somewhat more subtle.

Will try to measure. All those tiny spots, hope it'll work.

indman · « **Reply #12 on:** September 17, 2018, 02:21:59 pm »

Quote from: indman on July 01, 2018, 12:31:48 pm

Remove DZ1 = with zener-diode 6V8; DZ2 6-pin marked V05.To give power on a tester without remote elements. If the problem remains, then YOU have damaged the ATMega324 processor. His replacement and a new firmware is necessary.

Bighouse,already I wrote earlier how quickly to define malfunction.

flodo · « **Reply #13 on:** September 17, 2018, 02:32:04 pm »

Good idea indman! Yes Bighouse, instead of measuring you can simply remove DZ2 and see if the Tester still shows an voltage.

flodo · « **Reply #14 on:** September 20, 2018, 09:44:26 pm »

does someone have already dumped the original fw?

eliocor · « **Reply #15 on:** September 20, 2018, 11:14:58 pm »

Quote from: flodo on Today at 21:44:26

does someone have already dumped the original fw?

it seems to me that you have dumped a protected device, hence read data is not valid...

indman · « **Reply #16 on:** September 21, 2018, 07:56:41 am »

The Chinese original firmware ATMega324 for clones of LCR-TC1,TC6,TC7 are protected from reading of Lock by bits! Don't suffer, it won't turn out to remove them. If only who has available an electronic scalpel and the corresponding equipment for reading of the opened crystal.

zappenduster · « **Reply #17 on:** September 27, 2018, 11:02:44 am »

@flodo I put a multimeter (Aneng AN8008) in line. I bridged the multimeter while tc1 is in on-state. When tc1 shot down i removed the short and measured about 15uA sleep current.
Your 0.11mA Standby seem to be the 0.2mA i measured (range about 0.13 - 0.19 mA). By adding a 33k resistor to the 7805-output i got it to 15uA sleep, see my first post. But i don't know how reliable this is...

Here are some notes (which were new to me) for tc1-repairer , gathered by others:
DZ2 = TVS Diode Array = SRV05-4 (on some pcb its silk-screened ZD2)
U5 = DC-DC controller = SD6271 Step-Up Current Mode PWM Converter. Marking ALxxx (xxx = three digit lot-number)

tc1 schematic from azure: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=521336
tc1 schematic from indman: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=521411

That makes it a lot easier to get a broken tc1 back on track.

Mechatrommer · « **Reply #18 on:** October 07, 2018, 06:06:05 pm »

i bought this TC1 unit with expectation it is the same as M328 variant that i bought and worked charmingly earlier, but now my brother is using it now so i have to buy for myself. it turn out this is different atMega324 with STC15W104 chip, this turn out to be nightmare. and then i found this thread. after back and forth reading this thread i managed to get something from STC-ISP...

Quote

Checking target MCU ...
MCU type: STC15W104
F/W version: 7.2.5T

Current H/W Option:
. Current system clock source is internal IRC oscillator
. IRC frequency: 32.975MHz
. Wakeup Timer frequency: 36.825KHz
. Do not detect the level of P3.2 and P3.3 next download
. Power-on reset, use the extra power-on delay
. RESET pin behaves as I/O pin
. Reset while detect a Low-Voltage
. Thresh voltage level of the built-in LVD : 2.66 V
. Inhibit EEPROM operation under Low-Voltage
. CPU-Core supply level : 3.74 V
. Hardware do not enable Watch-Dog-Timer
. Watch-Dog-Timer pre-scalar : 256
. Watch-Dog-Timer stop count in idle mode
. Program can modify the Watch-Dog-Timer scalar
. Do not erase user EEPROM area at next download
. Do not control 485 at next download
. Do not check user password next download
. TXD is independent IO
. TXD pin as quasi-bidirectional mode after reset
. P3.3 output HIGH level after reset
. Testing time: 2017-9-22

. MCU type: STC15W104
F/W version: 7.2.5T

Complete !(2018-10-08 01:17:05)

if i choose STC15L104W as demonstrated by earlier experimenters, i wont get any report from the chip.

the problem when i got this unit is the shorted C11, so i changed with 100nF, no more short, but when battery is applied, lcd turn on white for half a second or so and then random garbage before turned off immediately. pressing start button do nothing. sometime the tester did turned on and firmware on mega324 did start, but its just luck. after reprogramming STC15W104 with frodo's tc1_u4_v0.3.1.hex, now its totally blank. removing and applying battery, there is no more white screen, no start button respond nothing. ah F the STC chip what was that? support us people of China guaranteed powerful home grown business FU so much so for anti disturbance super strong chip.

earlier i removed the STC chip and connect Vbat pin to the next pin controlling the boost dcdc chip (AL673 marking), the atmega did start but halted at welcome screen its like waiting for signal on either P3.3/PD2 or P3.2/PD1 i suspect to start measurement. i have to experiment later. i think i will remove the STC chip and glue it to blank space on the pcb so it can wave dick all day long all its like. i need to find a way to start the atmega chip the hard way. or anybody else can help me make program for the STC15W104 chip? i will be gratefull, for now i dont have time to play/install with Keil or whatever. i just want it to work and then move on.

btw,
1st picture: thermal imaging superimposed when shorted C11 is installed. the SD6271 got hot 73degC as registered by my camera.
2nd picture: how i connect the STC15W104 to USB-UART converter. need few experiment though since warning from people to use 3.3V rail, 5V may damage the fucked up super strong STC. it turned out i just use 5V UART and it just worked fine.
3rd picture: the fucked up super strong anti disturbance STC15W104 chip made home grown in China, please support it people of China. i really pissed off can you imagine by now?

thanks to people directly or indirectly contributed to this thread esp OP zappenduster, frodo and others, but your FW doesnt work with mine

and schematics providers indman and azure.
edit: added 4th picture with its IO state to PD1/PD2 from my crude test.. and the mega fw wont start by simply toggling PD1 pin, so there must be the right sequence to turn it on

prakash_kadri · « **Reply #19 on:** November 09, 2018, 03:34:10 am »

@zappenduster, I had same issue with my T7. Replaced C11 and C12 with 100nF 100V and 4.7uF 100V. Now it is working. Thank you very much for sharing the fix.

funkervoigt · « **Reply #20 on:** December 21, 2018, 01:11:18 am »

Hi !
I also have an defective TC1 Tester and followed your fabulous troubleshooting tips here.
The unit didn´t startup, i checked the capacitors C11 and C12, and the zener-diode DZ1. They seem to be OK.
After that i removed the TVS Array DZ2. Now the Device boots up (display flickers a few times when starting) but shows a cell voltage like in the picture from "bighouse".

For my understanding: Is it correct, that after removing DZ1 and DZ2, the ATMega should work normally, otherwise it is damaged (by overvoltage) and needs to be replaced ?

Thank You !

Attilator · « **Reply #21 on:** January 04, 2019, 09:33:38 am »

Hi,
I am lucky and got a fully functioning TC-1 unit. My question is about setting the shutdown time to 25sec.

I see in the manual that both P1 and P2 need to have ZEROs. Could you please suggest where this ZERO PIN is located? Just want to be safe before soldering.

Thanks.

amunro · « **Reply #22 on:** August 17, 2019, 11:25:28 pm »

I know this is an old thread, but it seems a good thread to append my experiences to! I recently bought two TC1 LCR testers. One was fine, while the other was difficult to turn on, and then it just would not turn on. So just spent the evening removing components and testing them. What I found was similar to others; U5 gets hot. However my issue was a short on the 5v rail, rather than the 35v rail. I was seeing a short of about 9 ohms. Thought it would be a shorted capacitor; not just from this thread, but its a common issue on lots of smt circuits. I could not find anything else hot, which was strange (mind you my room is quite warm where I was working, which does not help). The caps are really small and time consuming to remove and put back so wasted lots of time on that. Anyhow turns out it was the SRV05-4; when removed from the board it had 9 ohms between vcc and ground, and on the pcb, the short had gone. Furthermore, as soon as plugging in the battery the display fires up with the normal startup. Anyhow not wishing to experience failures because of the removal of the V05, I quickly disconnected the battery. V05 (as printed on the chip) are dirt cheap from China in a SOT23-6 package; got 10 of them ordered for £1.80, and they should turn up in 2 or 3 weeks to the UK. I don't mind waiting as it will be handy to have some spares incase of a repeat or incase I destroy one with a charged capacitor!

Which brings me back to why was it faulty straight from ebay? I suspect it was a return where someone might have damaged it, and requested a return. Then the seller just stuck it back in stock without checking it. Alternatively the SV05 was just bad?

amunro · « **Reply #23 on:** August 18, 2019, 07:59:57 am »

Also some of my capacitor parts were different to zappenduster. What I wrote down as I was testing:
c8 = c11 = c12 = 5uF
c9 = 16nF
c10 = 9 uF (slight out 10uF?)
c14 = c15 = 10 uF

Looking at what spec of 4.7/5uF 0805 capacitors are available, they seem to only go up to 16v. 0805 is 2mm x 1.25mm so that quite an achievement for such a small device. However for c11/c12 I measured 32v (and circuit diagrams above say 35v), so thats way under specified. Thus ordered some 50v 10uF, similar to what zappenduster mentioned, and will swap them out for 1 x 10uF, and add a decoupler of 100nF with 50V spec.

I know I am rambling here, but this thread was really useful to fix my unit, and hopefully my experiences will help others.

amunro · « **Reply #24 on:** September 25, 2019, 07:22:49 am »

My saga continues. The SV05s turned up from the slow boat from China (£1 for 10 of them). Soldered it in and still have an issue. Seems there is still a short on the 5V rail to ground (tested with an ohm meter), but not a sufficient short to pull the 5v down and to cause U5 to get hot. After some fault finding, I lifted pin 27 (avcc) of the atmega off the board and the short went away. So looks like the atmega324 is at fault. Ordered some more and will wait for them to turn up from China ($1.40 each).

In the meantime decided to learn about atmega flashing as I am going to need to flash the new atmega when it arrives. Soldered some pins onto the LCR-TC1 for the ISP port. Bought a USBASP programmer off ebay for not much money, installed avrdude (I use ubuntu so just install it via apt). Disconnect the LCR-TC1 battery and connect up the USBASP; it finds the atmega fine; tried to read the eeprom and flash; avrdude reads it and then reports the file is zero bytes (don't remember the exact message). Seems the lock bits are set. Did some reading up on lock and fuse bits (or bytes); understand these now. Decided to erase the atmega via avrdude; can't read the eeprom/flash anyway, so might as well. Then try and flash some new firmware. Discovered indman's LCR archives on yadi.sk and downloaded some firmware, which works (but the chip is broke so can't fully test); both the Markus Reschke firmware and the original firmware he posted (9/16/2019) flash and boot fine. Many thanks to indman for collating and making available these firmwares.

This unit I got off ebay, but was faulty on arrival so I got a refund on it. Thus its sitting round doing nothing so figured its worth fixing and experimenting with. Even trying different firmware on it. I bought another to replace this faulty one so its not as if I am desperate to get it fixed.

Again another ramble, but hopefully my hard earned time learning all this will be useful to someone!

amunro · « **Reply #25 on:** October 10, 2019, 06:59:25 am »

Posting an update. So I received some atmegas from China which look like fakes. One of them does not have a circle near pin 1 which is really suspect. Anyhow, ordered one locally from RS Components in the UK, which was pretty reasonable and had free shipping (if I had known that I would have ordered from them). This flashes fine using a USBASP (with the latest firmware); you need to use -B 5 for the slower rate comms with avrdude. I will try the Chinese atmegas with a crystal at some point just to confirm they are fake; if they do work they are not new from Atmel/Microchip! As I was testing the fake atmegas, I used a break out board and just soldered pins 1 thru to 6 to allow the ISP flashing. A nice diagram here https://www.kanda.com/avr-isp-circuits.html of what is required (need a 100nF capacitor and a 10k resistor on the board). Once I flashed the Rs Components atmega I then undersoldered it from the breakout board and onto TC1. Low and behold we have a working TC1.

So to summarize, SV05 had a short pulling the 5V line down; replaced that. Still had a short, but not as bad. I then had the issue as shown in the photo by Bighouse, although my issue was with pins 1 and 2. Lifted pin 27 (AVCC) of the atmega off the board and short gone. Replaced both of these components. Thus I would say if you have the issue as shown with Bighouse you might need a new atmega. Used indman's LCR-TC1 original firmware on yadi.sk (date 9/16/2019).

Hope my hard earned effort helps someone! Was pulling my hair out with the fake atmegas!

Attached a photo of the breakout board patched into a 6 to 10 pin ISP adapter. 10k resistor on the top and 100nF capacitor is a smd soldered on the bottom of the board.

capitainekurck · « **Reply #26 on:** November 13, 2019, 03:36:56 pm »

Hello all

I new on this forum.
I bought one of there tester on ebay.
I receive it today it work 5 or 10 minutes and it fail. i was trying to check some resistor and led to test it (not capacitors) and suddenly it stop to work. it don't turn on any more. The battery is full load. when i push the button to power it on, the screen become white ( it normally black when it power off) and it turn black few seconds after.

Is it the same problem as yours or for you the display stay black ?

regards
L.S.

quinhomvs · « **Reply #27 on:** December 01, 2019, 02:50:52 pm »

Hi , I am from Brazil , my TC1 multtest , reads the components , but when there is no component connected shows the measurement as in the attached figure, someone already had a similar error .

Translate.

madires · « **Reply #28 on:** December 01, 2019, 03:35:45 pm »

That means there's a small current flowing between the probe pins, possibly caused by the SRV05-4.

Del · « **Reply #29 on:** December 27, 2019, 03:58:27 pm »

Hello. I'm sorry, I'm using a translator . Can you share the compiled hex and EEP firmware ? I wanted to update the firmware but broke the tester . Compiled the firmware from MARKUS, the device is working, but there are no functions IR and ZENER diode , . Thank you in advance !

madires · « **Reply #30 on:** December 27, 2019, 05:28:15 pm »

If you like to run the m-firmware please use the settings for the TC-1 listed in the Clones file.

Del · « **Reply #31 on:** December 27, 2019, 05:37:03 pm »

I can't do it . Errors . 324pa processor

madires · « **Reply #32 on:** December 27, 2019, 05:48:30 pm »

Have you set the correct MCU model in the Makefile?

Del · « **Reply #33 on:** December 27, 2019, 06:10:26 pm »

Yes, of course, I was able to collect a simple firmware . The problem is to create config.h . Might not have version 1.34 , but I have tried all 1.34-1.38 . Sorry, but for me it is not quite clear, I do not really understand English , and I work with hardware and not the software part.

Del · « **Reply #34 on:** December 27, 2019, 06:16:59 pm »

Could you at least share the config.h and Makefile and specify version 1.3 x Markus ?

madires · « **Reply #35 on:** December 27, 2019, 06:19:12 pm »

There's a Russian forum: https://vrtp.ru/index.php?showtopic=16451.

Del · « **Reply #36 on:** December 28, 2019, 03:57:51 pm »

What and in what file should be corrected to freeze occur only once, after pressing the button ? And then the tester should be turned off . And at me the screen is displaced on nekkolko pixels up and to the left, that is it is necessary to shift it down and to the right - as it to consult.

madires · « **Reply #37 on:** December 28, 2019, 04:12:14 pm »

You can use LCD_OFFSET_X and LCD_OFFSET_Y to adjust the display's offset. What do you mean by "freeze"?

Del · « **Reply #38 on:** December 28, 2019, 04:32:16 pm »

Quote from: madires on December 28, 2019, 04:12:14 pm

You can use LCD_OFFSET_X and LCD_OFFSET_Y to adjust the display's offset. What do you mean by "freeze"?

Sorry, I'm using a translator

. freezing is wrong , I meant a single measurement . insert the component into the pad, press the button, see the readings and after 10-20 seconds the device will turn off itself .

LCD_OFFSET_X and LCD_OFFSET_Y to adjust the display's offset - this in what file to edit ? $:-\$

madires · « **Reply #39 on:** December 28, 2019, 10:02:38 pm »

LCD_OFFSET_X and LCD_OFFSET_Y are set in the display section in config_644.h (ATmega 324/644/1284). For a single measurement you would have to modify main() since there's no setting for that.

Del · « **Reply #40 on:** December 30, 2019, 06:45:03 am »

Quote from: madires on December 28, 2019, 10:02:38 pm

config_644.h

SUPER ! everything worked out ! thanks

Quote from: madires on December 28, 2019, 10:02:38 pm

modify main()

This setting is in flash tc1_u4_v0.3.1.hex ?

madires · « **Reply #41 on:** December 30, 2019, 10:28:35 am »

I've meant main() in m-firmware's main.c.

Del · « **Reply #42 on:** December 30, 2019, 12:15:25 pm »

in main.c. -- if (MissedParts >= CYCLE_MAX)

which in config.h

#define CYCLE_DELAY 10000

#define CYCLE_MAX 0

Super ! now the device turns off after 10 seconds, after the 1st measurement

Dronhom · « **Reply #43 on:** January 27, 2020, 06:23:26 am »

Had a previously mentioned problem when the tester always shows around 5 V ghost voltage between 1-2 or 1-3, and the problem couldn't be solved by re-calibration etc. Based on advice here, I took off zener diodes DZ1 and DZ2 - and the problem disappeared! After that I checked DZ1 and found it in good working condition, but DZ2 was short. Thanks to all contributors to this topic for useful information.

klausES · « **Reply #44 on:** March 01, 2020, 01:24:02 pm »

Is it possible to deactivate the automatic switch-off P1-P2 for 15, 20, 25 seconds (25 seconds default) with this tester ?

I would prefer to switch it off manually with the button.
Or at least shutdown on e.g. 60 seconds ?

madires · « **Reply #45 on:** March 01, 2020, 02:42:33 pm »

Yes, by reprogramming U4 and switching to k or m-firmware.

klausES · « **Reply #46 on:** March 01, 2020, 02:50:33 pm »

OK thank you.

To do this, I would first have to deal intensively with this topic. $:-\$
Let's see how much time I can and must invest.

Von Wuellmann · « **Reply #47 on:** March 04, 2020, 08:00:29 pm »

Hi!

I also have a Longruner brand TC1 that has the same problem, this only measures a cell voltage, this 5.04v case Whatever I put in the the thing. Nor can I have it enter calibration mode.

Looking at this same post about the answers, I managed to verify the DZ1 and DZ2 and these work correctly, so I had come to the conclusion that I need to change the atmega324pa. I am from Argentina and it is difficult to get this microcontroller in the market, can there be someone else I can replace? also another query, if I do get to buy 324 fro

Geert · « **Reply #48 on:** March 04, 2020, 09:02:54 pm »

Is there a newer firmware available for the TC1 ?
My tester has version 2.12k

madires · « **Reply #49 on:** March 05, 2020, 09:36:42 am »

Quote from: Von Wuellmann on March 04, 2020, 08:00:29 pm

Looking at this same post about the answers, I managed to verify the DZ1 and DZ2 and these work correctly, so I had come to the conclusion that I need to change the atmega324pa.

Have you tried with DZ1 and DZ2 removed?

madires · « **Reply #50 on:** March 05, 2020, 09:45:17 am »

Quote from: Geert on March 04, 2020, 09:02:54 pm

Is there a newer firmware available for the TC1 ?
My tester has version 2.12k

That's a modified k-firmware (modified by the manufacturer). I don't know if there's a newer version, but I'd recommend to upgrade to the OSHW firmware (k or m). And don't forget to reprogram U4 (https://github.com/atar-axis/tc1-u4) or replace it with a small circuit (https://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.kicad.tgz).

ceut · « **Reply #51 on:** March 05, 2020, 04:55:00 pm »

Quote from: Mechatrommer on October 07, 2018, 06:06:05 pm

i bought this TC1 unit with expectation it is the same as M328 variant that i bought and worked charmingly earlier, but now my brother is using it now so i have to buy for myself. it turn out this is different atMega324 with STC15W104 chip, this turn out to be nightmare. and then i found this thread. after back and forth reading this thread i managed to get something from STC-ISP...
Quote
Checking target MCU ...
MCU type: STC15W104
F/W version: 7.2.5T

Current H/W Option:
. Current system clock source is internal IRC oscillator
. IRC frequency: 32.975MHz
. Wakeup Timer frequency: 36.825KHz
. Do not detect the level of P3.2 and P3.3 next download
. Power-on reset, use the extra power-on delay
. RESET pin behaves as I/O pin
. Reset while detect a Low-Voltage
. Thresh voltage level of the built-in LVD : 2.66 V
. Inhibit EEPROM operation under Low-Voltage
. CPU-Core supply level : 3.74 V
. Hardware do not enable Watch-Dog-Timer
. Watch-Dog-Timer pre-scalar : 256
. Watch-Dog-Timer stop count in idle mode
. Program can modify the Watch-Dog-Timer scalar
. Do not erase user EEPROM area at next download
. Do not control 485 at next download
. Do not check user password next download
. TXD is independent IO
. TXD pin as quasi-bidirectional mode after reset
. P3.3 output HIGH level after reset
. Testing time: 2017-9-22

. MCU type: STC15W104
F/W version: 7.2.5T

Complete !(2018-10-08 01:17:05)
if i choose STC15L104W as demonstrated by earlier experimenters, i wont get any report from the chip.

the problem when i got this unit is the shorted C11, so i changed with 100nF, no more short, but when battery is applied, lcd turn on white for half a second or so and then random garbage before turned off immediately. pressing start button do nothing. sometime the tester did turned on and firmware on mega324 did start, but its just luck. after reprogramming STC15W104 with frodo's tc1_u4_v0.3.1.hex, now its totally blank. removing and applying battery, there is no more white screen, no start button respond nothing. ah F the STC chip what was that? support us people of China guaranteed powerful home grown business FU so much so for anti disturbance super strong chip.

earlier i removed the STC chip and connect Vbat pin to the next pin controlling the boost dcdc chip (AL673 marking), the atmega did start but halted at welcome screen its like waiting for signal on either P3.3/PD2 or P3.2/PD1 i suspect to start measurement. i have to experiment later. i think i will remove the STC chip and glue it to blank space on the pcb so it can wave dick all day long all its like. i need to find a way to start the atmega chip the hard way. or anybody else can help me make program for the STC15W104 chip? i will be gratefull, for now i dont have time to play/install with Keil or whatever. i just want it to work and then move on.

btw,
1st picture: thermal imaging superimposed when shorted C11 is installed. the SD6271 got hot 73degC as registered by my camera.
2nd picture: how i connect the STC15W104 to USB-UART converter. need few experiment though since warning from people to use 3.3V rail, 5V may damage the fucked up super strong STC. it turned out i just use 5V UART and it just worked fine.
3rd picture: the fucked up super strong anti disturbance STC15W104 chip made home grown in China, please support it people of China. i really pissed off can you imagine by now?

thanks to people directly or indirectly contributed to this thread esp OP zappenduster, frodo and others, but your FW doesnt work with mine and schematics providers indman and azure.
edit: added 4th picture with its IO state to PD1/PD2 from my crude test.. and the mega fw wont start by simply toggling PD1 pin, so there must be the right sequence to turn it on

Hello,
I have exactly the same problem on my brand new LCR TC1 (DOA).
No power on, only charging, and 22mA of continous current draining from the battery .
There is no voltage on the switch when not pushed (pin1 of U4), and it seems that it's U4 who drains that 22mA, so I think that U4 is blank or something like that.
But don't know how to flash it...

No problem on capacitors C11/12 but I have changed them to a 15µF/100V
No problem on diode array, neither on zener.

Someone has succeed to fix similar problem ?

Thanks !

ceut · « **Reply #52 on:** March 05, 2020, 07:12:27 pm »

So with only the U4 with only the power pin only on it (PIN2 Vcc and PIN4 GND), I have my "famous" 22mA continous draining.

I don't know why they use a MCU for power managing but it seems to be a bad MCU.

Also I don't know how to bypass this to power on all.

I have tried to apply +5V on the Atmel and I have the boot logo on screen, but nothing else, seems to wait for something and I think it's a link with this bad MCU.

ceut · « **Reply #53 on:** March 06, 2020, 07:20:07 pm »

I have reflashed the STC with the 0.31 hex and a modded USB serial adapter: no more 22mA draining from it, and it starts when press switch, but freeze on the boot logo.

I think I have to find another Atmel firmware to solve my problem.

So it was really a Dead On Arrival: the STC was flashed with something corrupted or wrong flash.
(After emailing and uploaded a video for them, the store where I bought it send me a new one, but wait again for about 3 weeks).

ceut · « **Reply #54 on:** March 06, 2020, 09:16:08 pm »

Final words from me: I have flashed the Markus 1.34, and it's working, but I'm not a big fan of it

I think I will not use it, and waits for the new one.

Hope that someone will find and post the "famous" original STC firmware then we can put the original graphical firmware

madires · « **Reply #55 on:** March 07, 2020, 02:26:52 pm »

https://yadi.sk/d/yW8xa5NJgUo5z/LCR%20%D0%A2%D0%A1-1/Firmware/Original, but I don't know if it will run with the alternative U4 firmware. BTW, the "original" tester firmware is a modified k-firmware with more graphics and less functions. The only additional feature is the IR decoder supporting just one protocol (the m-firmware does about 15). It's a trade-off between fancy graphics and features.

ceut · « **Reply #56 on:** March 08, 2020, 12:57:33 am »

Quote from: madires on March 07, 2020, 02:26:52 pm

https://yadi.sk/d/yW8xa5NJgUo5z/LCR%20%D0%A2%D0%A1-1/Firmware/Original, but I don't know if it will run with the alternative U4 firmware. BTW, the "original" tester firmware is a modified k-firmware with more graphics and less functions. The only additional feature is the IR decoder supporting just one protocol (the m-firmware does about 15). It's a trade-off between fancy graphics and features.

Hello,
Yes, I have tried this one, and in fact it's the original graphical firmware for the Atmel 324pa: it starts but freeze on boot logo with the alternative U4 firmware - I have not found the original U4 fw, it seems to be keep securely somewhere

For the m-firmware, it is good, but for me not very user-friendly

I have an old LCR T4 which I found better (I have put the latest fw from www.mikrocontroller.net).

Will wait for the new one and hope that it will work

(so I will keep this one for spare part)

ceut · « **Reply #57 on:** March 16, 2020, 03:51:04 pm »

Received the new one today, shipping was fast, despite of corona virus !

The new one works flawlessly.
A difference with the previous one: the battery was at about 60% and it has directly booted when I have pressed the button.

Will try to understand what U4 really tells to the Atmel for unlocking the boot of it.

The color screen is very readable, I like it.

cuistots · « **Reply #58 on:** April 02, 2020, 05:15:08 pm »

hi i have a ts7h wich a problem, could you tell me for repair it.
lot of thanks

madires · « **Reply #59 on:** April 02, 2020, 05:21:16 pm »

I'd suggest to check the power supply circuitry first.

cuistots · « **Reply #60 on:** April 02, 2020, 05:42:20 pm »

could you tell wich ref to verify ?

madires · « **Reply #61 on:** April 02, 2020, 05:53:57 pm »

U5 should be a 5V voltage regulator. Check in and out.

cuistots · « **Reply #62 on:** April 02, 2020, 06:07:36 pm »

u5 is good when a usb is connected 6.35v in and 5v out.

madires · « **Reply #63 on:** April 02, 2020, 06:19:19 pm »

Does display show weird stuff when USB is connected?

cuistots · « **Reply #64 on:** April 02, 2020, 06:22:06 pm »

no it's the same of photo.

madires · « **Reply #65 on:** April 02, 2020, 06:39:46 pm »

The next step is to check the signal lines for the display. Any bad solder joints? If you have a scope also check the SPI signals.

cuistots · « **Reply #66 on:** April 02, 2020, 07:35:53 pm »

no bad solder joints.
and i haven't a scope.

madires · « **Reply #67 on:** April 03, 2020, 09:18:27 am »

In that case you could try another display. IIRC, it's a ST7735.

cuistots · « **Reply #68 on:** April 03, 2020, 10:00:47 am »

Here is the reference of the lcd display, I will try to uncloud it to see its driver

cuistots · « **Reply #69 on:** April 03, 2020, 10:18:48 am »

it's exactly my problem:

https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg2168986/#msg2168986

madires · « **Reply #70 on:** April 03, 2020, 01:07:48 pm »

Then give it a try and add the two MLCCs.

cuistots · « **Reply #71 on:** April 05, 2020, 11:13:46 am »

the mlcc is already on the board.
i don't understand the problem

madires · « **Reply #72 on:** April 05, 2020, 12:13:26 pm »

Power the display module with 5V and check the output of the 3.3V regulator.

indman · « **Reply #73 on:** April 05, 2020, 12:49:40 pm »

Quote from: cuistots on April 05, 2020, 11:13:46 am

the mlcc is already on the board.
i don't understand the problem

If 3.3V regulator normaly works - with a very high probability, the source of this problem may be a malfunction of the U1 level converter chip
What is the marking on her case?

cuistots · « **Reply #74 on:** April 05, 2020, 01:23:11 pm »

this u1

cuistots · « **Reply #75 on:** April 05, 2020, 01:39:57 pm »

the 3.3V regulator normaly works.

indman · « **Reply #76 on:** April 05, 2020, 01:54:36 pm »

U1- the 74HC573; 74HCT573 is an 8-bit D-type transparent latch with 3-state outputs
Try replacing this chip. Another option is to remove this chip and connect the ATMega outputs directly to the display lines through 10kΩ resistors.
They are already on the display board. But this option is only at your own peril and risk.

Krafte · « **Reply #77 on:** April 19, 2020, 03:13:09 pm »

Yesterday, I got a shiny new TC-1 directly from China
I successfully got a 1.38m firmware running and testing components seems to work.
However, the LCD keeps flickering and the device turns randomly off. Also, the menu is not accessible by double pressing the button.
I think the reason is the stock firmware on U4. I tried to replace it with the custom one. But it seems the chip is not responding to the programmer.
I tried everything I could imagine , different PCs different uart adapter, all combinations of power on cycles for U4, double and triple checking the connections and pinouts, but nothing helped.
Anybody with same experiences? Any advice apart from replacing U4 by the proposed circuit of Markus?
The only thing that's a little strange are markings on the chip. It is "STC 16L104W".

UPDATE:

I got the chip to respond to me using my RPi 3 and stcgal (I strongly recommend this tool). It reported as STC15L104W.
However, flashing was not possible -> it always stopped while switching baud rates.
Finally with baud rate 1200 it was flashing, slowly but successfully

Kamlakkannan · « **Reply #78 on:** August 15, 2020, 10:11:02 am »

Hey, I just got the lcr t7 from China yesterday(after almost 3 months). It worked for sometime then it just displayed a white blank screen. After sometime it worked, but then again it displayed just white blank screen. This process repeated and now I am stuck with something that just displays a white screen. I checked the capacitors they aren’t short. The battery is good and I don’t know what to do next, so can you please help me.

Kamlakkannan · « **Reply #79 on:** August 15, 2020, 10:13:20 am »

And again after sometime it started working.

Kamlakkannan · « **Reply #80 on:** August 15, 2020, 10:32:39 am »

And now again just a white screen

alfagulf · « **Reply #81 on:** October 23, 2020, 04:18:59 pm »

I would like to add my experience with the TC1 that I bought from Banggood as a replacement for another unit which I zapped by connecting a charged high voltage capacitor by mistake

.
The new unit arrived faulty.

The unit did not power up, so I assumed the battery is dead and need to be recharged, which I did, but still pressing the start button did nothing.

I contacted them and they offered a refund which I accepted.

However I suspected the problem is around U4 (STC15W104) since it manages the start button and sends a signal to the boost converter U5 to start.
I noticed that pin 3 (P3.5) is not going HIGH when I press the button which of course the reason why it is not powering up.
I first reprogrammed U4 with the alternative firmware https://github.com/atar-axis/tc1-u4 , but that did not change any thing.
I then replaced U4 with the one I had in my first faulty unit. I started to have some intermittent success where the unit will power up sometimes and shuts down unexpectedly.

I then did more testing around the push button when I noticed C13 a debounce capacitor that had its resistance rather low (around 30K).
I removed it and the tester worked like a charm.
However I then replaced it with a good 100nF capacitor to keep the debounce function.

The U4 which I remove (I suspected to be faulty) turned out not faulty, I found out that by reprogramming it to output a 1Hz pulse on all ports which it did.
So I guess the problem for me was the faulty ceramic C13 capacitor.

I hope this information might help some of you.

Thanks

dvd4me · « **Reply #82 on:** November 05, 2020, 03:01:00 am »

Hello,

I just got today the TC1 from Bangood and it was defective, not turning on.
I found this post and after measuring the caps on the battery or the +3.7V rail, nothing wrong.
Plugging the battery made the screen to briefly turn on.
At the power on button, I noticed there was no voltage on the button contacts, just a very low 0.3V.
Putting 5V at the output of the U3 regulator made the screen to turn on but the boot stops at the daniu logo.

I just saw the post before me and noticed the C13 warning it might be leaky.
Removed the C13 and now it powers up at the insertion of the battery, yey!
Measuring the voltage at the power button is 3.8V ! So that's the normal voltage it should be on a normal tester.
I just put the cover back and that's it for now.

Now it works, see the second picture.

shved · « **Reply #83 on:** November 08, 2020, 03:11:37 pm »

A friend gave me TC1 with bulged battery and some damage.
I've cleaned it up and swapped in used samsung mobile phone battery. Changed c13 as a precaution. Everything works, as far as i can check. But stand by draw is around 20mA. Is that normal? Do i need to add a a battery cutoff switch? I have several LC, RLC, ESR, ... meters, but with external power(no battery only USB or 12v PSU), so i plan to use it for away jobs witch are quite infrequent.
My point is: the tester will be always "flat" when i grab it.
Any advise?

madires · « **Reply #84 on:** November 08, 2020, 05:02:15 pm »

That stand-by current is much too high. A classic power switch would be a simple fix. If you want to run one of the OSHW firmwares (k or m-firmware) you can replace U4 with a small circuit with two BJTs and the stand-by current will be about 5µA. With U4 the current should be around 0.2mA.

shved · « **Reply #85 on:** November 08, 2020, 11:19:21 pm »

Thanks madires.
I think I've fixed it. Now the stand-by current is around 0.2mA.
The problem was in the caps C6 & C7. The caps turned in to resistors and loaded the battery and 5V rail through the diodes. I don't quite know where the energy went, the caps didn't heat-up. I've tracked them down because 5V rail read too low(~4,5V) and battery check on boot showed the wrong voltage. To isolate the issue I've disconnected the diodes in turns, when 5V came back clean, I knew immediately to check the caps!
Also, the factory where they assemble the bloody things uses some reactive flux and doesn't clean it off. I strongly suspect that it's a factor, seen that before.

Anyway, anyone who has excessive stand-by current(around 20mA) check the caps C6 and C7! And I advise to wash the flux off the boards.

a_kiler · « **Reply #86 on:** November 13, 2020, 02:56:41 pm »

Hi, everyone.

Like most of us here I unfortunately damaged my brand new T7-H. Capacitor dead screen... sounds familiar?

Thx to advice:
@zappenduster: I bought 10uF capacitor; (didn't use it)
@indman: I removed DZ1 and DZ2 and... success, the screen is on. But sth else strange (for me) happend.
Tester works "like new".

Calibration: pass
Capacitor: pass
LED: pass
IR: pass
Even removed DZ2 - zener diode: pass

So if DZ2 is ok, DZ1 must be failure.

Oh, BTW - my is tester is a little bit different (pictures included) and DZ2 is 6V8C, DZ1 is V5L. I hope datasheet ic correct?

How can I examine DZ1?

@zappenduster said earlier:

Quote

ZD1 = zener-diode 6V8 ; DZ2 6-pin marked V05. Some pcb miss those two elements - maybe earlier layouts...

Is it possible the tester will work normally without DZ1 DZ2 or should I expect the unexpected.

madires · « **Reply #87 on:** November 13, 2020, 03:16:07 pm »

Yep, the tester works also fine without the input protection (DZ1 and DZ2). DZ1 should be a 6.8V TVS (not shorted = OK).

belzrebuth · « **Reply #88 on:** December 18, 2020, 02:32:29 pm »

I did the charged capacitor trick on mine so now it's dead..
DZ2 is certainly faulty and I've also found some shorted ceramics in there as well.
In total I've removed capacitors C14,C15,C24,C21,C23.
I haven't yet measured DZ1 but I've removed it for good measure.

I've also tested the 5V regulator out of circuit and it's working.

The problem is that the meter only boots when I'm applying 5V externally in the place of the 5V reg output.
When it boots it shows there's a DC source between terminal 2 and 3.
When connected to a USB plug only the red charging LED lights up but the meter is dead.

I think I'm probably having a problem with other stuff as well like the DC-DC section or else.

Since the MCU is probably working what might be going on with the power stuff?
How did I manage to save the MCU and I have a problem in the PSU section.
There is no input voltage to the 5V regulator when I'm connecting the USB plug so no wonder the meter is dead.

What could be the culprit here?
Would it be fixable?

madires · « **Reply #89 on:** December 18, 2020, 03:52:57 pm »

Presumably the ATmega's pins used for terminals #2 and #3 are shot and maybe also the control MCU U4. You can check the DC/DC converter by enabling it manually.

belzrebuth · « **Reply #90 on:** December 18, 2020, 05:12:00 pm »

Thanks for your reply madires.Really appreciate your help.
I get about 21.5V where I should be getting about 37.. (D2)
How should I enable the DC converter manually?!

I noticed that if I connect my bench PSU to the battery terminals providing 3.7V if I press the button I get about 0.35A current draw and then after a short period of time almost no current draw(0.9mA) or so.
Forgot to mention that I get about 3.4V at the 5V regulator input and 1.7V at it's output.
The regulator input and the 35V rail which is 21.5 maybe tell that the DC-DC converter might be faulty?!
I also get about 25ohms between the 5V rail and ground which seems low but then again the meter boots when I give it 5V and it's current draw is not excessive.

madires · « **Reply #91 on:** December 18, 2020, 05:38:06 pm »

If the boost controller is an AL693 pull up pin 4 (to the battery's voltage). That pin is connected to a pull-down resistor and pin 3 of U4.

belzrebuth · « **Reply #92 on:** December 18, 2020, 06:56:54 pm »

The marking of U5 is AL715..

madires · « **Reply #93 on:** December 18, 2020, 07:22:11 pm »

No idea about that one, but I'd guess it's quite similar.

belzrebuth · « **Reply #94 on:** December 18, 2020, 08:24:46 pm »

Nothing changed when I pulled the pin4 to 3.7V.
Same input to the regulator.
If nothing else down the line is preventing the 9 or so volts to appear maybe the DC/DC is bad.

Maybe I should just buy this IC and replace it, as long as it exists somewhere which I'm not sure of.
Seems like a non-standard part available in China only.

If I power the thing with 5V directly shouldn't it measure components though?
I mean if my MCU is also bad (which btw is an ATMEGA 644 not 324) I could just buy a new meter and discard this..
Are the capacitors I've removed critical to the operation when powered directly from 5V?

indman · « **Reply #95 on:** December 19, 2020, 07:16:20 am »

Quote from: belzrebuth on December 18, 2020, 05:12:00 pm

I noticed that if I connect my bench PSU to the battery terminals providing 3.7V if I press the button I get about 0.35A current draw and then after a short period of time almost no current draw(0.9mA) or so.
Forgot to mention that I get about 3.4V at the 5V regulator input and 1.7V at it's output.

It is very likely that your MCU is damaged. Take a multimeter and check the resistance of the PA0-PA3 test ports against + 5V and the ground. You can also check the resistance of pin 4 (VCC) to ground.
AL619 (AL715, AL718) this is the marking of the SD6271 chip

belzrebuth · « **Reply #96 on:** December 19, 2020, 10:53:39 am »

Vcc to Ground is around 25ohms.
I mentioned it before and it seems weird that it's too low but when I power the thing directly with 5V its current consumption is within spec at around 350mA.
PA0 to Vcc 560k
PA1 to Vcc around 20οhms
PA2 to Vcc around 112ohms
PA3 to Vcc 2.2k

I wonder why they used a 644 in my revision instead of a 324 which is almost triple the price. PCB version is 2.0.

indman · « **Reply #97 on:** December 19, 2020, 11:42:29 am »

belzrebuth From + 5V, the serviceable tester consumes from 24.6mA to 44mA. You have a defective processor, you need to replace it. It is not difficult if you have the skills to solder such things. Better to buy the same ATMega644. Chinese friends very often install those parts that are currently in stock. In terms of cost, the difference between chinese 324 and 644 is very small. They earn more due to the large number of devices sold.

belzrebuth · « **Reply #98 on:** December 19, 2020, 01:58:08 pm »

Ah okay..thanks:)
I thought the current draw was normal all this time

I'll replace the MCU and post back.

shved · « **Reply #99 on:** December 19, 2020, 03:21:31 pm »

belzrebuth, I've also had excessive power draw. Double check the caps, esp. C6 & C7. Also check for corrosive flux. Give a quick read to the rest of the thread.

bob91343 · « **Reply #100 on:** December 20, 2020, 07:34:02 pm »

My unit works okay but the display is bad. It displays data as expected but the screen has become hard to read. I can change viewing angle for some improvement but still it's bad. It's an early monochrome.

I bought another but want to fix this one, as it seems more accurate.

shved · « **Reply #101 on:** December 20, 2020, 08:13:11 pm »

If you have a mono lcd panel - that's a different model.
Most designs using those kind of displays have a contrast POT or a set of resistors witch are responsible for contrast. Check for all of those, + check for panel damage + check for corrosive flux damage.
If you indeed have a different model - give this thread a quick read and try to find threads and schematics for your specific or a similar unit.

vk3ohm · « **Reply #102 on:** December 23, 2020, 03:40:34 am »

Does anybody have a document that explains the principle of operation of these, or similar, devices? I would love to give a presentation to my radio club about how they work, but I've been unable to find any information anywhere.

ledtester · « **Reply #103 on:** December 23, 2020, 05:37:02 am »

Quote from: vk3ohm on December 23, 2020, 03:40:34 am

Does anybody have a document that explains the principle of operation of these, or similar, devices? I would love to give a presentation to my radio club about how they work, but I've been unable to find any information anywhere.

The site for the project:

https://www.mikrocontroller.net/articles/AVR_Transistortester

Go to the Downloads section and get the manual in the language of your choice, e.g.:

https://github.com/svn2github/transistortester/tree/master/Doku/tags/english/ttester_eng112k.pdf

ledtester · « **Reply #104 on:** December 23, 2020, 08:35:43 am »

Should add that this is the main eevblog forum thread for these devices:

https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/

madires · « **Reply #105 on:** December 23, 2020, 10:33:45 am »

Quote from: ledtester on December 23, 2020, 05:37:02 am

https://github.com/svn2github/transistortester/tree/master/Doku/tags/english/ttester_eng112k.pdf

That mirror is obsolete. Please use https://github.com/madires/Transistortester-Warehouse.

billy_gr · « **Reply #106 on:** January 09, 2021, 03:13:56 pm »

Hi,

Measured a cap without discharging it and now i got a T7 that measures a cell voltage between pins 1 and 2

Removed both the DZ1 DZ2 but the issue remains. Should i assume that the ATmega is toasted ?

Thanks in advance

madires · « **Reply #107 on:** January 09, 2021, 03:32:15 pm »

Yep, it's toast. You can replace the ATmega or buy a new tester, whatever is simpler or cheaper for you.

billy_gr · « **Reply #108 on:** January 09, 2021, 05:08:20 pm »

Quote from: madires on January 09, 2021, 03:32:15 pm

Yep, it's toast. You can replace the ATmega or buy a new tester, whatever is simpler or cheaper for you.

Thank you !!!

speedsterharry · « **Reply #109 on:** April 09, 2021, 12:43:00 pm »

Hi all, I'm new to the forum.

I found this thread thanks to the amazing power of search engines, and was glad to make my TC1 work again (it was only detecting a 5V cell whatever what was connected to the leads). The SRV05 was dead, after removal the TC1 worked like before.
What kind of problem will the lack of ZD2 mean to my TC1 tester ? I don't want to fry it for good !!!

Thanks, the amount of good info available here is FANTASTIC !

EDIT: I'd like to upgrade my TC1 firmware. Does anyone in France, preferably near Lyon who does that kind of service ? I'm about to get 2 new TC1 just for spares and would like to have them upgraded as well when I get them. I don't want to do it myself, I don't have the tools nor expertise to do that (and don't want)

Or maybe one of the developers sends the TC1 with latest firmware ?

madires · « **Reply #110 on:** April 09, 2021, 01:19:43 pm »

ZD2 (SRV05) is a weak over-voltage protection. The tester works also fine without it, but make sure that you always discharge capacitors before connecting to the tester.

belzrebuth · « **Reply #111 on:** June 07, 2021, 11:57:25 pm »

Is there a programming header on the TC-1 or should I directly attach wires to the MCU?

I destroyed mine with a charged capacitor and I replaced the atmega but I now need to re-upload the firmware.
With an older tester I needed to solder wires directly to the 328p in order to update it.

madires · « **Reply #112 on:** June 08, 2021, 09:18:35 am »

You just need to solder an ISP header (unpopulated footprint at the top).

belzrebuth · « **Reply #113 on:** June 08, 2021, 11:14:23 am »

Thanks madires.
Do you maybe have an avrdude command for the atmega 644?
I'm thinking of using the m-firmware.
I don't know what fuse settings I need to set on the ATmega 644.

belzrebuth · « **Reply #114 on:** June 08, 2021, 12:28:09 pm »

Here are the commands I've gone with; fuses set as follows:
avrdude -c usbtiny -p m644 -U lfuse:w:0xff:m -U hfuse:w:0xd9:m -U efuse:w:0xfc:m
avrdude -c usbtiny -p m644 -U flash:w:ComponentTester-TC1.HEX
avrdude -c usbtiny -p m644 -U eeprom:w:ComponentTester-TC1_eeprom.HEX

I think I've managed to upload the firmware fine since I got a "Bye!" on the LCD.

I then powered the unit with 3.7V on the battery pins but the tester still doesn't work.
The LCD just flashes in white.
I think there's something wrong with my "U4" maybe.
I tried reprogramming that as well but my chip is scratched down and I can't see the markings on top.
I've set various ICs as DUT but no configuaration recognises it..
I've gone with STC15W104, STC15L104, STC15L104W, STC15W104 so far..
My FTDI adapter outputs a VCC of 3.56V instead of 3.3V would this be the fault maybe??

madires · « **Reply #115 on:** June 08, 2021, 12:44:08 pm »

You can run "make upload" after setting the programmer in the Makefile. And for the fuses it's "make fuses". Regarding U4 you can alternatively replace U4 with a simple two-transistor circuit (https://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.kicad.tgz) which also has a lower quiescent current.

belzrebuth · « **Reply #116 on:** June 08, 2021, 12:48:38 pm »

The STC-ISP managed to recognise the IC as STC15L104W but I still can't get it to upload the firmware.
I have my 6V8 diode removed from circuit while the DZ2 is installed.
Can this prevent the tester from working.
I only have a 6v8 zener in a thru hole package.
Can I install this one?
Does it need a high wattage (1W or so) or any 6V8 diode will work?
Sorry for all these questions madires, I really appreciate your help.

edit: I can't even re-recognise the IC when I try to "check MCU" from the STC software.
It did it once and I can't make it to repeat it.
So no wonder it can't upload the .hex file.
I need to power the DUT under a certain timing frame or something?

edit2:
To define what my problem is:
If I power the tester with 3.7V from my bench supply it starts up and measures components fine.
Power consumption is around 240mA when this is happening which I think is a bit excessive.
So I let cycle thru "Probing.." around 3 times and then it displays "Bye" and shuts off.

If I press the button I get about 200mA current consumption again but all I get is a white screen and then the tester shuts off.
What could be causing this behavior?

I need to mention that I put diode D0 backwards once I removed it to check it.
I powered up the unit one or two times with that diode placed backwards, I hope I haven't managed to destroy my 2nd atmega.

belzrebuth · « **Reply #117 on:** June 08, 2021, 04:52:02 pm »

@madires
Do you have a picture or something of your TC-1 U4 replacement mod?
I did download it but it's kicad files which can't be opened with Eagle and I can't open it with Kicad either cause there are some libraries or footprints missing as it says.
I think I'm going to remove U4 as I can't seem to be able to program it or even check its status.

madires · « **Reply #118 on:** June 08, 2021, 06:21:22 pm »

The Zener/TVS plus DZ2 are a weak overvoltage protection and can be removed without any problem. DZ2 is often damaged in case of a charged cap. 240 mA are much too high. So there's some bad component. The TC-1 mod archive includes three images.

belzrebuth · « **Reply #119 on:** June 08, 2021, 06:35:50 pm »

I quickly bodged your replacement circuit in a small piece of proto and it worked

Current consumption is now 200mA or so when it's on, I find it a bit high as well.
But it also works with a semi-discharged battery so I guess it's okay now?!

What a typical current draw should be if external power is applied at the battery terminals?

madires · « **Reply #120 on:** June 08, 2021, 07:01:44 pm »

I'm not sure about the exact current draw of the TC-1 since the boost converter also creates the 40+ V for the Zener check. OP zappenduster measured 300-400 mA which are quite high. The standard circuit needs about 20mA @ 5V on average. Add the backlight, the Zener test voltage and a possibly low efficiency boost converter.

belzrebuth · « **Reply #121 on:** June 08, 2021, 07:05:17 pm »

I could try applying 5V at the output of the 5V regulator and measure the current draw at that rail to check if it's within this figure (20mA) or so.

Another thing I wanted to ask if it's normal for the tester to repeat a component test for 5 retries instead of just freezing at the component measurements.

With a component at the input terminal it just shows the result and then repeats the measurement for 5 times.
Without a component it does 5 retries displaying "no component" and then switches off.

madires · « **Reply #122 on:** June 08, 2021, 07:23:06 pm »

Either press the start button for > 300 ms when powering on or enable UI_AUTOHOLD in config.h. There are many configuration switches to optimize the firmware for your needs.

indman · « **Reply #123 on:** June 09, 2021, 05:44:32 am »

Quote from: madires on June 08, 2021, 07:01:44 pm

OP zappenduster measured 300-400 mA which are quite high.

Yes, this is the amount of current I measured on my TC-1 with a 3.7 V power supply at the time of launch. Later the current value can be kept at the level of 150mA.This is quite high,so the circuit requires a fairly capacious battery. From the +5V power supply, the circuit together with the display backlight consumes up to 30-50mA.

peteb2 · « **Reply #124 on:** August 25, 2021, 09:08:44 pm »

So to take the thread into another (massive apologies) direction.... i have owned a TC1 for the last 4+ yrs & today just when i need it the battery is discharged... So as usual i've set it onto charge but this time.... NoGo! So here's my quandary:

Replace the internal rechargable LiOn looking thing...& if i do that i might as well replace the ZiF socket that is hammered on '1,2,3' on a thing with a now yellowed coloured case with soldering iron burns *OR*... do i stump up for a new (probably badly made knockup rendition) *OR* is there a better alternative?

I'm thinking a USB interface breakout module that interfaces with workbench PC that runs what the TC1 did and does in a GUI on screen, the same kind of thing but more accuracy ...please i'm a tech who fixes a lot of gear & yes i should at least fix my own old TC1, but is there a better alternative by any chance & not waste time o this used to death thing? I already own a Peak DCApro semiconductor USB curve tracer tester but it appears to have a lower range of ability than my old TC1... tia

madires · « **Reply #125 on:** August 26, 2021, 09:36:22 am »

You could buy a new TC-1 and add a switch for the LiPo. If you're looking for alternatives check out the AY-AT clones, e.g. GM328A, and the Hiland M644. And if you program one of the two OSHW firmwares you'll get even more features. BTW, there are two mods for the TC-1 to make it compatible with the OSHW firmwares. The hardware mod also reduces the quiescent current to a few µA.

Feliciano · « **Reply #126 on:** August 27, 2021, 01:10:47 pm »

If you easily find the spare parts you can try to fix the one you have, following the tips on the previous 5 pages (in most cases to replace the protection diodes ZD1 and/or ZD2 if you forgot to discharge a capacitor, as well as some caps that tend to leak or go short because the close to 40V on the Vz section of this device). If you end replacing the MCU, remember to reprogram or replace U4 with the alternative circuit (two transistors plus some resistors and diodes) before attempting to flash m-firmware or k-firmware.

Or because these ttesters are inexpensive, you can buy the one that better suits your particular needs. Here, the main models at a glance: https://github.com/madires/Transistortester-Warehouse/blob/master/Documentation/English/Clone-Comparison-Chart.pdf

Felipe Lacerda · « **Reply #127 on:** October 17, 2021, 02:02:37 am »

Quote from: Feliciano on August 27, 2021, 01:10:47 pm

you can buy the one that better suits your particular needs. Here, the main models at a glance: https://github.com/madires/Transistortester-Warehouse/blob/master/Documentation/English/Clone-Comparison-Chart.pdf

TC1 needs the mod to accept opensource firmware... does T7-H need it too? what is the best choice?
According to the table are the models that support upgrade to the 644.

*I want to buy a new one, but I haven't found any on Aliexpress already with the 644.

F1RVC · « **Reply #128 on:** November 20, 2021, 10:36:32 pm »

Hi, does somebody already had on a TC1 (M-tester V2.12k) a Zener value displayed always (with no component connected) at the startup?. All other functions look to be ok, if I put other kind of component , it is ok, but with no component it detect a zener and with a zener the measure is bad.
I checked 37v (approx) is here, the zener voltage is going to PA4 thru a divider by 10, Should have 3,7v here but input look to be pulled down by PA4 and the low voltage is displayed like a zener voltage. Also the Ref voltage 2.5V (TL431) is also pulled down to 0V on PA3 by the 324PA, if I isolate PA3 the ref voltage rise up to 2,5V. If I isolate the PA4 , it also diplay a zener voltage at startup with 0V value !
I do not tremember having done a bad measure with non discharged component , TC1 did it by itself one day at the bootup.

Before trying to change the ATMEGA with a new one and flash it with the original TC1 firmware provided on this thread, maybe I missed something more easy to fix this TC1?
Any advice or clue will be apreciated.
If I start in this way , I will probaly tweak it with alternative k firmware and hardware U4 mod later (but before I would like to fix it ) ...

madires · « **Reply #129 on:** November 21, 2021, 12:59:15 pm »

PA3 and PA4 should be in HiZ mode. If both suddenly short the input to ground then they most likely let the magic smoke out.

F1RVC · « **Reply #130 on:** November 21, 2021, 05:13:00 pm »

That is my first thought too, but what is the link between both of them? If a problem would have been occured on PA4 (static or capacitor discharge, etc...) why PA3 is down too ?

madires · « **Reply #131 on:** November 21, 2021, 05:36:15 pm »

I can only speculate. An over-voltage could also damage neighboring IO cells on the MCU die.

distefanom · « **Reply #132 on:** December 17, 2021, 09:04:07 am »

I would ask anyone who has the circuit made using a couple of transistors, to replace U4 so allowing me to use the free firmware kindly available here.
Since I don't have kikad on my PC, I would like if anybody could make me a screenshot of the complete circuit (I don't need the PCB layout) so I could replicate it on a bareboard.
Thanks to anybody who can help.
Mario

madires · « **Reply #133 on:** December 17, 2021, 11:41:28 am »

Please see https://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.pdf!

chris2u · « **Reply #134 on:** January 29, 2022, 03:44:20 pm »

I just bought a TC1 recently....Generally all seems good....Although the micro USB connector was too far recessed for the cable to reach properly!....And don't expect the PCB to sit right down on it's supports..Probably due to the display being mounted too far off the circuit board, or maybe the supports are in the wrong place..

The zener test voltage is 23.1V (Not over 30v as other units are) and am wondering if this is normal for this model ??
This unit does not have the largish high voltage transformer but has 2 small inductors in the power supply section.

Attached is a photo of the PCB.

madires · « **Reply #135 on:** January 29, 2022, 04:14:00 pm »

Your TC1 seems to be another variation with two separate boost converters. To verify the output voltage for the Zener test you could reverse engineer the boost converter (IC and feedback voltage divider).

chris2u · « **Reply #136 on:** January 30, 2022, 07:09:15 am »

Looking at the first set of specs from AliExpress, it mentions 20V for zener....Then later specs show 30V..So yes, like a covid 19 variant ...Needs another booster!.

https://www.aliexpress.com/item/4001208715581.html?spm=a2g0o.detail.1000023.1.67d0549fikoqen

indman · « **Reply #137 on:** January 30, 2022, 08:57:32 am »

Quote from: chris2u on January 29, 2022, 03:44:20 pm

The zener test voltage is 23.1V (Not over 30v as other units are) and am wondering if this is normal for this model ?

Yes, this is normal, because as a DC-DC converter chip is used SDB628, which can adjust the output voltage range to a maximum of 28V! Exactly the same chip is used to produce a 7-9V input voltage for a 7805 stabilizer.

Felipe Lacerda · « **Reply #138 on:** February 01, 2022, 04:49:15 pm »

Quote from: chris2u on January 30, 2022, 07:09:15 am

Looking at the first set of specs from AliExpress, it mentions 20V for zener....Then later specs show 30V..So yes, like a covid 19 variant ...Needs another booster!.

https://www.aliexpress.com/item/4001208715581.html?spm=a2g0o.detail.1000023.1.67d0549fikoqen

TC-T7-H is the best version available? Is this seller reliable?

chris2u · « **Reply #139 on:** February 02, 2022, 05:41:32 am »

What I think would be nice is if you could change the colors allocated to the three inputs.
This way I could have (1) Red, (2) Black, (3) Green, which was the color of the supplied leads and test hooks.
It's would be a lot easier to identify what lead is what and what is base, collector and emitter and so on if things are the same colors throughout.

ATM I'm having to order purple test clips from China as there are not too many around locally.
Maybe some firmware genius could come up with a solution..

madires · « **Reply #140 on:** February 02, 2022, 02:38:25 pm »

The m-firmware supports color coded probes/test pins and you can set whatever colors you like.

joseff701 · « **Reply #141 on:** February 14, 2022, 04:03:59 pm »

Hi, I tried a capacitor and after the tester did not turn on anymore, I removed the zener diodes DZ1 and DZ2, now it turns on but does not work, on 1 and 2 it says there are 1.46v. if anyone can help me understand what broke.

madires · « **Reply #142 on:** February 14, 2022, 05:56:36 pm »

Toasted MCU IO pins, grilled by a charged cap. Can be fixed by replacing the MCU (and programming a firmware).

bob91343 · « **Reply #143 on:** February 17, 2022, 05:59:53 am »

My TC-1 consistently is fooled by a capacitor I have. This capacitor tests fine on my two bridges but when it comes to the TC-1 it doesn't know what to make of it. It will say unknown or give a completely incorrect value. Other capacitors from the same batch test fine.

distefanom · « **Reply #144 on:** March 04, 2022, 11:53:44 am »

Hi Madires!
After a looooong time, the micro finally arrived from china, on my workbench.
I can now program the uP with the kind free firmware available around here.
BUT, before doing it, I need now ask:
With the free firmware, do I need to replace the U4 with the two-transistor circuit?
When I program the IC, which fuse map do I need to use, so I could (theoretically) reprogram it ?
I mean that I could -after programming the uP- reprogram it as many times needed to test different FW releases?
I'm afraid that, with the wrong fuse map, after the first programing it will lock out itself, and I need to buy another uP.

Please let me know
Thanks
Mario

madires · « **Reply #145 on:** March 04, 2022, 01:15:14 pm »

To make the TC1/T7 compatible with the reference design you can replace U4 with the two-transistor circuit or reprogram U4 (https://github.com/atar-axis/tc1-u4). For the fuse bits simply run "make fuses" after editing the Makefile (both OSHW firmwares).

distefanom · « **Reply #146 on:** March 09, 2022, 07:04:46 pm »

Hi, Madires
If I don't want to do the MAKEFILE, since I Have eXtreme Burner only in my PC,
(see the attached image)
Do you know what values I should put in the Fusemap, so the uP can be reprogrammed anytime?
Please let me know
ciao
Mario

madires · « **Reply #147 on:** March 09, 2022, 07:37:45 pm »

For ATmega324 and 16 MHz quartz crystal:
- hfuse 0xd9
- efuse 0xfc
- lfuse 0xf7

distefanom · « **Reply #148 on:** March 09, 2022, 09:27:23 pm »

Thanks, Madires !!!

I'm missing "Lock fuse" and "calibration"
Leaving them as FF and blank is enough?

madires · « **Reply #149 on:** March 09, 2022, 09:56:38 pm »

Yep, simply ignore those two.

belzrebuth · « **Reply #150 on:** March 18, 2022, 01:21:20 pm »

Is the zener diode test somehow disabled in the alternative firmware?
I tried testing a zener today (a 18V one) but no luck..

Gyro · « **Reply #151 on:** March 18, 2022, 01:25:19 pm »

The tester is only capable of putting out a maximum of 5V (and a little less in practice).

belzrebuth · « **Reply #152 on:** March 18, 2022, 01:26:50 pm »

Ahh okay.
Thought TC-1 could measure up to 20V zener or something..
edit:
@Gyro I think you may be mistaken.
TC-1 is able to test zeners so maybe my unit has a hardware problem since I've repaired it as can be read a couple of pages back in this thread.

I'm using firmware 1.34m.

madires · « **Reply #153 on:** March 18, 2022, 02:07:55 pm »

Quote from: belzrebuth on March 18, 2022, 01:21:20 pm

Is the zener diode test somehow disabled in the alternative firmware?
I tried testing a zener today (a 18V one) but no luck..

Quote from: belzrebuth on March 18, 2022, 01:26:50 pm

I'm using firmware 1.34m.

Have you enabled the Zener test in config.h? The settings should be:

Code: [Select]

#define HW_ZENER
#define ZENER_DIVIDER_CUSTOM
#define ZENER_R1         100000
#define ZENER_R2         12000
#define ZENER_UNSWITCHED

And in config_644.h:

Code: [Select]

#define TP_ZENER         PA4

You can find the required settings in the 'Clones' files.

madires · « **Reply #154 on:** March 18, 2022, 02:15:16 pm »

Quote from: belzrebuth on March 18, 2022, 01:26:50 pm

Thought TC-1 could measure up to 20V zener or something..

The older models go up to about 40V. Later models have a different boost converter good for 30V or so.

belzrebuth · « **Reply #155 on:** March 18, 2022, 03:16:25 pm »

If I haven't done anything to firmware I should assume the diode test is disabled by default?
Because I don't think I've configured anything; just transferred a hex file to the MCU IIRC..

indman · « **Reply #156 on:** March 18, 2022, 05:01:59 pm »

Quote from: belzrebuth on March 18, 2022, 01:26:50 pm

I'm using firmware 1.34m.

If you are using this firmware version(1.34m), then checking the zener diodes can only be done from the main menu in the item "Zener". Automatic zener testing, which is similar to the Chinese factory firmware, is available in newer versions of m-firmware.

Gyro · « **Reply #157 on:** March 18, 2022, 05:13:05 pm »

Quote from: belzrebuth on March 18, 2022, 01:26:50 pm

... edit:
@Gyro I think you may be mistaken.
TC-1 is able to test zeners so maybe my unit has a hardware problem since I've repaired it as can be read a couple of pages back in this thread.

Indeed I am. I'm clearly well out of date on these things, my apologies.

distefanom · « **Reply #158 on:** March 19, 2022, 09:12:23 am »

Hi Madires, this morning replaced the U4 with the 2 transistor schematic and I tried to flash the micro (see the enclosed images).
The programming has gone successful,
But all I get is that splash screen, which holds until I have the button pressed, and nothing more happens.
Maybe the firmware I used is wrong, but I don't have a link for the correct files,
Can you help?
Thanks

madires · « **Reply #159 on:** March 19, 2022, 11:06:56 am »

For the m-firmware:
- download source at https://github.com/madires/Transistortester-Warehouse/tree/master/Firmware/m-firmware
- see 'Clones' files for settings
- edit config.h, config_644.h and Makefile
- run 'make'
- run 'make upload'

distefanom · « **Reply #160 on:** March 19, 2022, 12:19:29 pm »

Sorry Madires, for my deep ignorance, so I still need help.
Keep in mind that my Transistortester is a TC1, which has an ATmega324 @ 16 MHz quartz crystal (see the enclosed shot of it, my previous posts you can see the PCB) and I have an old Win7 PC:

- I don't even know how to download ANY of those files from Github: even though, I'm a registered user, I can't find any "download" on any of those pages.
- I don't have any idea on how to compile the sources (if I could eventually download any of them) to have the right .eep and .hex files I need, to send to the micro via eXtreme burner.
I'm not a developer, so I don't know how to "makefile" these...

Could you or someone else help me with this harassment, since I would like simply to have those .eep and .hex files even the first edition is enough for me?

Many thanks

belzrebuth · « **Reply #161 on:** March 19, 2022, 12:52:51 pm »

To download you have to get to the master folder:
https://github.com/madires/Transistortester-Warehouse
and press code (green button).
I imagine that you need to have WinAVR or mingw64 or maybe both to be able to "make"..
Anyways I did run the command with default settings and I attached the output files (.eep and .hex).
Hope it helps you.

edit:
Default settings shouldn't work for because I just saw that default frequency is 8MHz..
Hmm..
I should recompile with 16MHz and reupload..
I could also wait for you to edit the Makefile to your needs and compile with that one maybe?
Let me know how I can be of help.

madires · « **Reply #162 on:** March 19, 2022, 01:12:56 pm »

Go to https://github.com/madires/Transistortester-Warehouse/blob/master/Firmware/m-firmware/ComponentTester-1.45m.tgz and click "Download" at the right side while not being logged in. And for getting started please see https://github.com/madires/Transistortester-Warehouse/blob/master/Documentation/English/FAQ.Feliciano.pdf. There's a ready-to-use k-firmware for the T7 (https://github.com/kubi48/TransistorTester-source/tree/master/trunk/mega644_T7_Mod) which could possibly also work with the TC1.

belzrebuth · « **Reply #163 on:** March 19, 2022, 01:23:41 pm »

Quote from: madires on March 19, 2022, 01:12:56 pm

There's a ready-to-use k-firmware for the T7 (https://github.com/kubi48/TransistorTester-source/tree/master/trunk/mega644_T7_Mod) which could possibly also work with the TC1.

Just tried to upload it to my TC1 and I bricked it so I don't think that firmware works with the TC1...
Is there any other .hex that can restore it now that I did what I did?

indman · « **Reply #164 on:** March 19, 2022, 02:09:45 pm »

Quote from: madires on March 19, 2022, 01:12:56 pm

There's a ready-to-use k-firmware for the T7 (https://github.com/kubi48/TransistorTester-source/tree/master/trunk/mega644_T7_Mod) which could possibly also work with the TC1.

Madires, k-firmware works only for ATMega644, it is not suitable for ATMega324.

Quote from: belzrebuth on March 19, 2022, 01:23:41 pm

Just tried to upload it to my TC1 and I bricked it so I don't think that firmware works with the TC1...
Is there any other .hex that can restore it now that I did what I did?

Here is a ready-made working firmware for the clone TC1 and ATMega324

madires · « **Reply #165 on:** March 19, 2022, 03:36:35 pm »

Quote from: indman on March 19, 2022, 02:09:45 pm

Quote from: madires on March 19, 2022, 01:12:56 pm
There's a ready-to-use k-firmware for the T7 (https://github.com/kubi48/TransistorTester-source/tree/master/trunk/mega644_T7_Mod) which could possibly also work with the TC1.
Madires, k-firmware works only for ATMega644, it is not suitable for ATMega324.

My bad. Some TC1s come with an ATmega324, some with an 644. MCU lottery.

This is one of the reasons I don't provide any ready-to-use firmwares. There are simply too many hardware variations to cover.

distefanom · « **Reply #166 on:** March 19, 2022, 04:00:05 pm »

Hi Indman!
thanks for your efforts, but the link you provided me won't me download it, since it says the file is too big and I need Yandex installed.
Which I did, but the installation program says that this program can't run in my region (Italy).
BTW the processor inside my TC1 is an Atmega324, as I said several times.
Personally, I don't think the .eep and .hex files should be so big, so maybe a direct link anywhere would be good enough.

distefanom · « **Reply #167 on:** March 19, 2022, 04:24:32 pm »

Hi Indman. Sorry I didn't recognize it

I successful programmed it in the Atmega 324. But I get kinda bootloop (see attached images) showing the first, then the second an then again the first
Also seems to me that the image is shifted 2 dots left and 2 dots up in respect of the display itself.
What's the meaning of the number shown?

indman · « **Reply #168 on:** March 19, 2022, 04:29:23 pm »

Quote from: distefanom on March 19, 2022, 04:24:32 pm

What's the meaning of the number shown?

This means that your device has a problem. Read advice from other owners on how to fix it.

belzrebuth · « **Reply #169 on:** March 19, 2022, 07:11:40 pm »

Quote from: indman on March 19, 2022, 02:09:45 pm

Here is a ready-made working firmware for the clone TC1 and ATMega324

Mine has a 644 and I think I already have v1.34 somewhere, I was hoping for a newer edition of the m-firmware.
I guess I need to roll my own..

distefanom · « **Reply #170 on:** March 19, 2022, 07:35:11 pm »

Hi indman, I think no.
Some weeks ago I broke my TC1 incidentally measuring a charged capacitor, I was sure it was already discharged.
I'm a hardware engineer, and I found several damaged components on the testing path, like the protection diodes including DZ1, DZ2 as well the other resistors that go to the uP I/O ports (see the enclosed schematic for reference).
Now they're all ok now, and changed the uP Atmega324 so I cannot imagine what else could be if not a FW problem.
Maybe I should learn how "compile" the firmware, as you said, to tailor the sources to my TC1 device needs, but at my age, I find a thing really hard to do, starting from zero, as I am.
I thought, as I already did with several other appliances, I felt it was way easier to find the already compiled FW and program it inside the micro.
But I have to say is really harder than I thought.
I'm still in the hope that someone else already has done it, and could kindly link me the firmware he/she used.
Many many thanks to those who can help

indman · « **Reply #171 on:** March 20, 2022, 07:14:51 am »

Quote from: belzrebuth on March 19, 2022, 07:11:40 pm

Mine has a 644 and I think I already have v1.34 somewhere, I was hoping for a newer edition of the m-firmware.

Here is the working firmware for ATMega644
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg3578117/#msg3578117

Quote from: distefanom on March 19, 2022, 07:35:11 pm

Hi indman, I think no.

But I still think you're wrong! The firmware that I suggested is 100% working and tested on a very large number of clones like yours. Here is another 100% working firmware in Russian(1.41m) for your clone. Try it and if the display shows the same messages as on 1.34m, then your device has a hardware problem.

Remove the protective diode assembly DZ2 for a while and check the operation of the firmware without it. I also advise you to check the quality of the soldering of the ATmega324 processor. Very often problems arise precisely for this reason. Check the resistances of each of the processor test ports(PA0-PA2) against +5V and GND. I also do not advise you to check the operation of the device with the USB charging cable connected.

distefanom · « **Reply #172 on:** March 20, 2022, 11:47:00 am »

Hi indman!
quote: "But I still think you're wrong!"
Trust me indman, I really HOPE I'm wrong since I would like to recover this device, and not throw it into the bin!
All the suggestions you give, like the DZ2 zener, all the protection diodes are already out of the PCB, as well to control the soldering joints of the I/O ports
Also there's no problem reading/verifying the uP at all.
This evening I'll try you Russian version, and let you know.
Thanks 4 the moment

stefanus · « **Reply #173 on:** April 19, 2022, 06:37:19 pm »

You forgot to check DZ2, (SRV05-4) ,when you tested capacitor without discharged, DZ2 will protect forward/reverse voltage, and mostly DZ2 will short. ATMega will saved all the time.

distefanom · « **Reply #174 on:** April 19, 2022, 07:20:20 pm »

I removed it already long ago.
It still won't work and the micro shows what's in the attached photo-
Of course it won't make any measurement

indman · « **Reply #175 on:** April 20, 2022, 12:59:59 pm »

Quote from: distefanom on April 19, 2022, 07:20:20 pm

It still won't work and the micro shows what's in the attached photo-

Once again I repeat to you, if you did not understand me before - your clone has a hardware problem and no other firmware will fix it! Use a multimeter to check the resistance of all measuring ports of the processor relative to + 5V and GND.

LesioQ · « **Reply #176 on:** June 18, 2022, 04:59:57 pm »

My tester TC-1 M-Tester died after a dozen of tests done (original factory graphical firmware).
The first problem I noticed was erratical behaviour - sometimes it booted OK but failed to test, sometimes it was hung-up on logo screen.
Sometimes the main screen display had pixel errors (image distorted).

Upon some testing I noticed it bahaves better if 5V supply is lowered somewhat. I ended up adding a Si diode right after (U3) 5V stabilizer with caps. Now Vcc is 4.2V.

It may be that communication with a LCD working on 3.3 Volt supply was causing problems.
Now it's testing OK, but fails to complete a Self-test - hangs at 7-16%.

Maybe someone can elaborate on that.

madires · « **Reply #177 on:** June 18, 2022, 05:58:24 pm »

The tester needs 5V to run properly. Possibly a power supply issue, e.g. a broken MLCC. Do you have a scope to check the output of the boost converter?

LesioQ · « **Reply #178 on:** June 18, 2022, 06:49:25 pm »

Sure I do. I was searching for some fluctuations on Vcc 5V, but it looks OK. HV is 39V, (after C13 & C14 replacement).
Vraw (5V stab. input) is about 9V.

madires · « **Reply #179 on:** June 19, 2022, 03:57:12 pm »

A dodgy display (ST7735)?

mtcaus · « **Reply #180 on:** July 09, 2022, 03:20:12 pm »

Solved the no power up issue. When the button is pressed, there is no display and Step-up/Boost IC at U5 is so hot. It could burn your finger. The fault is the Schottky barrier diode at D2. The diode with marking code SS18 (1A, 80V) was tested fine both in-circuit and out-of-circuit. Replaced it with SR2100 (2A, 100V) and the unit is working again. Measured the peak voltage of 52V at the cathode side of SR2100 Schottky diode when the button is pressed. Since the voltage rating of 1206 SMD capacitor at C11 is only 50V. Eventually C11 will give up. I replaced it with an electrolytic capacitor Rubycon 4.7uF @50v. I couldn't find a higher rated voltage of capacitor. Ideally should be like 100v. However, when I tested the Rubycon withstand voltage, it could go up to 100v. No wonder Rubycon capacitors are good. Anyway, fixed the unit by replaced two components at D2 and C11. See photo fixed.jpg.

From the transformer, when the button is pressed, there are two outputs, 9v (for powering the unit) and 37v(at least for Zener diode testing). See photo Bottom.jpg. Mine was like 2v on either path. Obviously there was a short somewhere. Through the process of elimination, I removed Schottky diode first. I got the 9V back. At first I thought ATMEGA324PA was the fault, but it was tested fine when applying 5V directly. See photo Top1.jpg and Top2.jpg. At first replaced D2 with SS24(2A, 40V) for testing. Obviously the voltage is not rated high enough. The diode was so hot and high pitch sound can be heard from the transformer when power up. Since I don't have any other SMD Schottky diode with a voltage rated that high. I used a through-hole Schottky diode SR2100 and there is enough space to install it. For the capacitor at C11, it will give up eventually if the peak voltage repeatedly go above the rated 50v 1206 SMD capacitor. This maybe the reason why people reported C11 shorted in the forum.

My LCR-TC1 is from the original creator. The original has 3 Chinese characters (浩祺心) on the top of the circuit board. See photo Top1.jpg. The component layout may be slightly different than yours since there are so many clones out there. However, the general layout is the same.

I have been troubleshooting this unit for a while. Replaced numerous Step-up/Boost IC ALxxx at U5 with different numbers. xxx are three numbers. The numbers do not matter if anyone who cares to know. Even bought STC15L104W chip at U4 and programmed it. By the way, I couldn't find the original U4 firmware. Luckily I didn't overwrite the original chip. Obviously none of them worked until I replaced Schottky diode at D2. The time and money spent may not justify, but the feeling of successfully fixed the unit is worth it. Hope this post will help someone out there.

masster · « **Reply #181 on:** August 09, 2022, 11:27:46 pm »

I bought today my TC1. As many other users before me, I calibrated the tester then started to check parts.
After maybe 8 parts measured, the tester turned off as usual by himself, but never came back on. It is dead. I didn't check any capacitor, only resistors, transistors, and a diode.
I thought the battery is low, although the tester showed 3.85V. I charged it on USB and after 10 minutes the LED turned from red to green. Yet still no luck. The tester is dead.
Full of confidence, I opened the case, hoping to change two capacitors and move on. But... surprise! Although on the outside, my TC1 looks identical to the rest of TC1's in this topic, on the inside there is another story. A totally different parts layout. See attached photo. I managed to read the codes on each IC and annotated the photo accordingly.
So my question is: how should I diagnose for the fault? Anyone happens to have the schematic for this version?
Many thanks in advance if you can help me.

masster · « **Reply #182 on:** August 10, 2022, 05:46:43 am »

Update:
The output of 78L05 (VCC) is shorted (3.5 ohms). What is the best method to decide which component is shorted? Capacitors, input protections, IR receiver, MCU, ATMEGA itself.

TurboTom · « **Reply #183 on:** August 10, 2022, 07:24:39 am »

If you have a thermal imager, attach a current limited lab supply to the shorted supply line (set to maybe 100mA) and observe what component heats up. This is also possible without such gear: if you use a sprayer (the type used for misting flowers) filled with isopropanol or ethanol and spray the board with a very thin layer of the liquid, you can usually observe where it evaporates first. Good luck!

masster · « **Reply #184 on:** August 10, 2022, 07:37:45 am »

78L05 has a maximum output current of 100mA with proper heat dissipation.
How much current draws the device on 5V when measuring?

madires · « **Reply #185 on:** August 10, 2022, 11:33:08 am »

I don't know the specific current draw for that model, but usually it's about 15mA on average for the 5V rail.

mtcaus · « **Reply #186 on:** August 10, 2022, 09:32:42 pm »

TC1 will very likely break down after continuous tests in a short period of time because it always generate high voltage for zener diode test every time. The components along that path simply cannot take it. Your unit is the newer design, but it's basically the same. Instead of one transformer with two outputs, your design simply uses two sets of inductors and step-up converters. By looking at the photo, you have a burnt resistor R24 circled in green. You should also check all the components circled in red. I saw your circuit online somewhere before. Just search around and you can find out the value for your R24.

masster · « **Reply #187 on:** August 10, 2022, 11:45:39 pm »

@mtcaus

Very good catch on R24. It would help to know its value.

I can't explain myself why the resistor R24 failed. "High voltage" is not 6000 Volts or so, maybe 30 Volts at most, and R24 should be in the kiloohms range. Moreover, I didn't insert any part in the K pin (cathode for Zenner diodes)

I have checked the components marked in red. They are all OK. With a thermal camera, when I press the TEST button, the 78L05 regulator and the 4 capacitors (2 on the input side and 2 on the output side) glow like fire...

indman · « **Reply #188 on:** August 11, 2022, 07:06:52 am »

masster,a malfunction in these clones with certain skills in repair and understanding of the principle of their work is found in a couple of minutes.

The schematic diagram of your clone will roughly correspond to the scheme on the LCR-T7H, only the numbering of the elements will be different. R24 will correspond to R13 on my circuit and will be 10Kohm.
If you have a heated 7805, then there is a high current consumption.We need to determine the cause.Remove the 7805 from the circuit and check its serviceability separately using an external power supply. Also, temporarily remove the U2 diode assembly(SRV05) and the 6V8A suppressor from the circuit. Then check with the multimeter whether there is a low resistance at the output of the 7805 (3.5 ohms)?

Per Hansson · « **Reply #189 on:** August 11, 2022, 08:56:15 am »

Quote from: mtcaus on August 10, 2022, 09:32:42 pm

By looking at the photo, you have a burnt resistor R24 circled in green. You should also check all the components circled in red. I saw your circuit online somewhere before. Just search around and you can find out the value for your R24.

Isn't it just installed with the bottom side facing up?

masster · « **Reply #190 on:** August 11, 2022, 09:31:43 pm »

@indman
Thank you for your reply. I know you researched this tester heavily. The only thing that keeps me from doing a better job in diagnosing the issue is the microscopical size of the parts. I wanted to minimize the intervention on the board because I really hate it working with heavy magnifying glasses for electronics or with a microscope.
Anyway, I have desoldered in turn the following parts: 78T05, the two filter capacitors on the 5V output, the input protections (6V8A and SRV05-4), and the IR receiver.
Shorted parts found: SRV05-4 and the IR receiver. Yes, I know. The latter being faulty was a total surprise.
I find that the quality of the parts used in these tester clones is deplorable (POS), hence the low price. In fact, the seller didn't offer any guarantee. Although after replacing the bad parts the tester will most probably work, it is very unreliable. Who knows what else will break? My advice? Don't waste the money on those China clones. Make one yourself with good quality parts, maybe in bigger size to avoid doing neurosurgery on the board, and definitely I would try finding a better input protection because right now if somebody is messing with the input pins by shorting them inadvertently or forgetting a cap is not discharged, he will look again(!) at a dead tester.

@Per Hansson
You are right. The resistor was soldered upside down. I measured it after desoldering. It has 10k indeed.

indman · « **Reply #191 on:** August 12, 2022, 07:20:47 am »

Quote from: masster on August 11, 2022, 09:31:43 pm

Shorted parts found: SRV05-4 and the IR receiver. Yes, I know. The latter being faulty was a total surprise.
I find that the quality of the parts used in these tester clones is deplorable (POS), hence the low price.

Your problem does not in any way confirm the low quality of Chinese parts, although such a reality certainly exists.
A short circuit immediately in 2 parts allows us to conclude that there was some surge of increased voltage, which these parts took over. Put it back in place 7805 (if intact) and turn on the tester without SRV05-4 and the IR receiver. The device should turn on and work without them.
Very often the culprit of similar malfunctions is static electricity.

Quote from: masster on August 11, 2022, 09:31:43 pm

Who knows what else will break? My advice? Don't waste the money on those China clones. Make one yourself with good quality parts, maybe in bigger size to avoid doing neurosurgery on the board, and definitely I would try finding a better input protection because right now if somebody is messing with the input pins by shorting them inadvertently or forgetting a cap is not discharged, he will look again(!) at a dead tester.

Of course, you are right that a thing made with your own hands will bring much more benefit and experience than a purchased one!
But on the other hand, thousands of Chinese clones work well for many people and they don't bother looking for other options.

masster · « **Reply #192 on:** August 12, 2022, 10:35:51 am »

@indman
I have soldered back in place just the 78L05 and 6V8A. The display came back to life, but instead of showing "No, bad part, or unknown part" message, it shows Cell 1.84V between pin 1 and 3.
I remind you that I didn't test any capacitor whatsoever from new. Moreover, when I worked on the board, I used an ESD wristband.

madires · « **Reply #193 on:** August 12, 2022, 12:13:11 pm »

Most likely the ATmega was damaged too.

indman · « **Reply #194 on:** August 12, 2022, 12:59:34 pm »

Quote from: masster on August 12, 2022, 10:35:51 am

I remind you that I didn't test any capacitor whatsoever from new. Moreover, when I worked on the board, I used an ESD wristband.

It takes a very good reason to make several parts malfunction at once.Wouldn't you agree?
If you rule out static electricity and an undischarged capacitor, it will not be easy to find the cause of such an occurrence with your clone.
I do not exclude the possibility that somehow in an incredible way the voltage that is created to test the Zener diodes (25V) hit the input of the measurement ports of the processor and knocked out the protective assembly, IR and the ports themselves.In my practice there have been several cases where the part for testing was placed on the K contact on one side and on one of the 1-2-3 test contacts on the other side.

masster · « **Reply #195 on:** August 12, 2022, 03:42:03 pm »

1) What is the maximum voltage/current supported by the input ports of ATMega?
2) Is there a better solution to protect the input ports against charged capacitors?
3) Is there a better solution to protect the input ports against wrongfully connecting tested parts? Fool proof and full proof.

indman · « **Reply #196 on:** August 12, 2022, 04:05:22 pm »

Quote from: masster on August 12, 2022, 03:42:03 pm

1) What is the maximum voltage/current supported by the input ports of ATMega?

This information can be found in the datasheet of the AVR. MaxVoltage -5.5V, MaxCurrent for 1 port - 40mA,for all ports -200mA

Quote from: masster on August 12, 2022, 03:42:03 pm

2) Is there a better solution to protect the input ports against charged capacitors?

You can replicate the protection circuit using a relay with 3 contact groups as shown in the Karl-Heinz manual.
But as correctly noted by the authors of the project - no protection provides a 100% protection guarantee. The same goes for the answer to your question №3

masster · « **Reply #197 on:** August 13, 2022, 01:58:55 am »

Quote

Most likely the ATmega was damaged too.

If the display says "Testing..." and after 5 seconds it shows "Cell, 1.40 V between pin 1 and 2" , is that definitive proof the ATMega is damaged?

indman · « **Reply #198 on:** August 13, 2022, 05:22:55 am »

Yes, this is one of the characteristic signs that one or more measuring ports of the processor are damaged. To make sure of this definitively, you can check the resistance of each port relative to GND and VCC. Provided that the SRV05-6V8A protective assembly is removed and nothing else is connected to the ports in parallel.You can also believe whether the nominal values of the measuring resistors 680ohm and 470k are in order. If they are in good condition, and the port resistance is very different, then this indicates damage to the processor.

masster · « **Reply #199 on:** August 14, 2022, 01:45:53 am »

I decided to remove the 6V8A and SRV05-4 to measure the resistance between each pin of ATMega and GND. See schematic below. Where there is no resistance value, the resistance is higher than 2 Mohm.
I find abnormal the resistance between VCC and GND, which is still low IMO. I have used an external power supply for VCC and I have measured a current consumption of 170 mA. That is way too high, over what 78L05 can deliver. Hopefully there is another faulty filtering capacitor on the VCC bus. I didn't remove them all. I still have hope that ATMega is not toasted.

Please have a look at my resistance measurements and tell me what else you find odd. I don't like the values on pins 34 to 37, corresponding to PA0 to PA3.

Right now, with external VCC supply and battery connected, I get the Cell of around 1.2V between 1 and 2. Sometimes I get a Cell between pin 1 and 3.