TC1 lcr-meter transistor-tester fix

[LeWidget]

Hi all. I was looking to get one of these testers but tossing up between the TC1 & T7. Which one is more useful, reliable, easier to repair if something goes wrong ?

[acerquax]

Hi all. I was looking to get one of these testers but tossing up between the TC1 & T7. Which one is more useful, reliable, easier to repair if something goes wrong ?

In the meantime I have two of these T7, I blowed up one of this devices by trying to measure a charged capacitor (  ) so a huge spike killed the analog input of the MCU!
I changed the MCU today and now we will see how good the different firmwares are.
No experience with the TC1 but if I understand the threat correct, these pcbs are almost the same.
 
Don't bring too much current into the MCUs 644 or 324 or whatever,
 the absolute rating for input current of this MCUs are strong limited!
Otherwise you need a microscope and a good soldering device and a good idea to get rid of the damaged MCU 

[acerquax]

With a microscope and a good soldering station I could replace the atmega32x with an atmega644.
I could flash the hex-files and eep-files(only test button) which indman suggested
 but after switching on the T7 I see only a white screen for some seconds!
Thats it!
What do I wrong?
Do I have to reflash the 15L104 as well?

[madires]

There are several variants of the T7. Please post a picture of the tester's PCB and also one of the display module (the side with LDO, levelshifter, etc).

[acerquax]

Voila'...
Thanks mate! (Dankschee)

[acerquax]

 

[madires]

That one needs a firmware update for U4 (https://github.com/atar-axis/tc1-u4) or a simple two-transistor circuit which replaces U4 (https://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.pdf).

[acerquax]

That one needs a firmware update for U4 (https://github.com/atar-axis/tc1-u4) or a simple two-transistor circuit which replaces U4 (https://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.pdf).

Thx mate..!
but
No flashing possible.....FTDI USB/UART connected,
started stc-isp6,
adjusted 12MHz ,
opened code file U4.hex--->
Download program.....>>> ..checking target MCU.................... nothing more! 

[indman]

acerquax, It is not necessary to reprogram U4, remove it from the board and save it to be able to return the factory Chinese firmware. Instead of U4 build a very simple circuit on 2 transistors, which madires suggested. It works much better and more reliably than the U4.

[madires]

... and the quiescent current is much lower.

[acerquax]

.....in the meantime......
I built up your transistor replacement U4.

What happens
The tester starts with the introduction menue
<<<Component Tester>>>
<<<LCR-TC1 v1.43m>>>
then it is displayed for a short time
Testing....
Bat 3.9V      VCC 4.98V
then >>>switching off

What is the functionality of this two transistors?
When I push the button
enable goes high (Pin3) ;
PD1 (Pin7) goes low;
PD2(Pin8) always High
as long as I see the introduction menue

Thats it... 

[madires]

What have you set for BAT_LOW? PD1 is the test button input (low active) and PD2 is the power control output (high active). U4's pin 3 (enable) is connected to the boost converter's 'enable' input. When you push the test button Q1 turns on the boost converter via the 'enable' signal. The ATmega is powered and starts running the firmware. One of the first things the firmware does is setting PD2 high. This keeps the 'enable' signal for the boost converter high, regardless of the test button. At the same time PD2 is also used as power source for the button input PD1, generating a high signal when the button isn't pressed. When the button is pressed Q1 turns on and switches Q2 to generate a low signal for PD1.

[acerquax]

Thx mate...
BAT_LOW? no idea what this means, maybe the problem?!!

What I measured, no more high at PD2 after the intro, that means for me no more power state locking and therefore no power for the MCU at all.


 

[indman]

What have you set for BAT_LOW?

Madires,  acerquax uses my modified version of m-firmware 1.43ModEn, which is posted on my yandex disk resource. BAT_LOW is set to a threshold of 3300 and that is not the reason for the shutdown.
Firmware 1.43Mod is tested by me personally on a similar TC1 clone and also by a very large number of other people and has shown itself to be very reliable and stable.

To acerquax:
1.Check again very carefully how well you soldered the new ATMega644 processor and cleaned the flux afterwards! This is the main reason that causes difficulties and problems for the owners of the device.
2.Show me the state of the fuses, which is read by your programmer from ATMega644?

To All!
The forum has 1 global thread "$20 LCR ESR Transistor checker project" which has many different experienced people participating and reviewing, including our esteemed author madires. So I don't see much point in creating several duplicate new threads with questions like "my TC1 or T7 tester doesn't work, what should I do?". Ask your questions about this project in the global thread and you will be answered quickly. And to look through a dozen new branches with the same questions I personally do not have any desire.

[acerquax]

Thx indman...

No problem to swing over to the threat you suggested.
I didn't managed the fuses at all!
I can't find your suggested firmware... :'(


[ Attachment Invalid Or Does Not Exist ]  

[indman]

acerquax
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg3578117/#msg3578117

[acerquax]

[indman]

What programmer and software are you using?

[acerquax]

I checked it with several softwares

AVR Burn-o-mat
and
myAVR Prog tool

My programmer worked always perfect in different projects! (Arduino,esp32...)

[Cartel]

whats it mean when it says battery 368mv365m on the screen every test?
I barely used this thing and it seemed way off from the lcr-t4.
now its more money wasted on china junk

[madires]

That means the tester measures those voltages between the probe pins and assumes an external voltage source. Typically this is caused by a bad SRV05-4 or by damaged MCU pins. Remove the SRV05-4 and check again.

[Cartel]

That means the tester measures those voltages between the probe pins and assumes an external voltage source. Typically this is caused by a bad SRV05-4 or by damaged MCU pins. Remove the SRV05-4 and check again.

I have a blue version. U5 gets very hot after just 1 test.

[indman]

Cartel,remove D1 and D2 from the PCB and turn on the tester without these parts. If nothing changes, the main controller is damaged.
All of these nuances are chewed up in detail in this thread several times on every page.

[iv3wjr]

Hi to all,

  first of all let me say THANKS to all of you for this amazing thread, I've learned a lot from reading.
  I'm owner of a TC-V2.12k. Mine worked fine until I forgot to charge the battery for... years . Now I replaced the dead battery with a new LP524558 3.7V 1450mAh battery. After full charge (red led, than green) pressing  the start button the device boots, the screen turns on but I see only the message "Charge the battery" with a (wrong) [ Vbat = 2.26V ] message. No way to calibrate, only that message.
  Now the question: is there a way to "reset" the device or to "force" a new calibration?
  Thanks for your time.

Bob

[csuhi17]

Hi to all,

  first of all let me say THANKS to all of you for this amazing thread, I've learned a lot from reading.
  I'm owner of a TC-V2.12k. Mine worked fine until I forgot to charge the battery for... years . Now I replaced the dead battery with a new LP524558 3.7V 1450mAh battery. After full charge (red led, than green) pressing  the start button the device boots, the screen turns on but I see only the message "Charge the battery" with a (wrong) [ Vbat = 2.26V ] message. No way to calibrate, only that message.
  Now the question: is there a way to "reset" the device or to "force" a new calibration?
  Thanks for your time.

Bob

Hi, have you measured the voltage of the replacement battery, is the device really fully charged?
Can you use it while charging?