TC1 lcr-meter transistor-tester fix

[gobi2000]

Yes. that's an LGT8F328. Pin 21 is SWD which is also part of the SWD programming interface (Gnd, Vcc, SWD, SWC, Reset). Pin 21 of a genuine 32-TQFP ATmega328 would be Gnd.

Have you found the pin out of this PCB?

[madires]

No, neither do I have that clone nor its schematic.

[gobi2000]

I measured a capacitor, which was discharged behind the multi meter and is now dead, so I wanted to know if it had any protection.

[Kim Christensen]

I measured a capacitor, which was discharged behind the multi meter and is now dead, so I wanted to know if it had any protection.

If you have the same device as slash14 posted then the protection device is probably D2 on that PCB which is similar to the SRV05-4 by ON-semi. D1 also looks to be part of the protection circuitry.

[SA]

Have you already tried with U2 and D1 (weak input protection) removed?

Yes, I replaced the U2 and D1 is fine.After replacing it came to life but showing cell from 1-2 pin. The mcu also heating. So I have to replace the atmega328p. But I need the compiled code and Fuse bits. I will be greatful if you please help me.

[SA]

I have fried my TC1 with charged capacitor. The MCU also fried. My TC1 comes with ATMega328p DIP IC. I am not an expert in but if I could get complied code, I would be able to fix it. Please help me

There are compiled versions out there. But on another note, while a pin or two might be fried, you may still be able to read the Flash and eeprom. (You need both) Then simply write it to a new chip.
Depends on whether the chip has copy protect enabled or not.

Can you please provide the link of the compiled code for tc1 with dip Atmega328p??  And where to find the fuse bits??
I have tried to read but the mcu is read protected 

[madires]

Yes, I replaced the U2 and D1 is fine.After replacing it came to life but showing cell from 1-2 pin. The mcu also heating. So I have to replace the atmega328p. But I need the compiled code and Fuse bits. I will be greatful if you please help me.

In case you're looking for an OSHW firmware: https://github.com/madires/Transistortester-Warehouse

[SA]

In case you're looking for an OSHW firmware: https://github.com/madires/Transistortester-Warehouse

I am unable to find suitable code for my device.
This one is my device:

[madires]

Sorry, I don't provide compiled firmwares.

[tedris]

hi ihave t7  I measured without discharging the capacitor. malfunctioned but i notice that 7805 in 0v so no give 5v. and i  connect  5v 7805 its run but not measured. i push button bur show same power voltage how solve this?
not measuring  why?

[madires]

Please post a picture of the PCB to help figuring out which specific model you have and if it got a genuine ATmega.

[tedris]

My board picture this thanks

[madires]

Your T7 is an early version and has a genuine ATmega. Remove ZD1 (6.8V TVS) and DZ2 (SRV05-4) and try again. If the tester still shows "Cell" then the ATmega is damaged.

[tedris]

hi i try it but not work it same. if i bought this chip is it run? it adapt my board? thanks for help sory my english is bad.

[madires]

You can replace the ATmega and program an OSHW firmware. You'll also need to reprogram U4 or replace it with a simple two-transistor circuit.

[indman]

You can replace the ATmega and program an OSHW firmware. You'll also need to reprogram U4 or replace it with a simple two-transistor circuit.

madires, tedris has an ATmega32 in the screenshot, it is not supported in the OSHW project.
tedris,you can only replace a damaged controller with an ATmega324 or ATmega644.

[MarkMLl]

In case you're looking for an OSHW firmware: https://github.com/madires/Transistortester-Warehouse

Since this is very much an FAQ, I suggest that that page could usefully have some specimen photos of supported boards possibly with a couple of arrows showing people what to look for.

MarkMLl

[madires]

Something like https://github.com/madires/Transistortester-Warehouse/blob/master/Documentation/English/Clone-Comparison-Chart.pdf?

[MarkMLl]

In the main repo I see a fairly prominent link to https://github.com/kubi48/TransistorTester-source/blob/master/picture-link.pdf

Particularly now that somebody has usefully raised a question based on a tester that /can't/ be upgraded from your repo I think that you could usefully have a "These are the testers known to work" link to the PDF you gave.

MarkMLl

[tedris]

Hello, I bought 3 atmega324pa chips, which file will I write to them when they arrive?  can you send a link?

[madires]

Regarding the additional control MCU U4 (STC15L104W) there are two options:
- reprogram: https://github.com/atar-axis/tc1-u4
- replace with two-transistor circuit: https://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.pdf
For m-firmware download the latest version from https://github.com/madires/Transistortester-Warehouse/tree/master/Firmware/m-firmware and use the settings listed in the Clones file (TC-1, old variant). Compile the firmware and program firmware and EEPROM. And don't forget to set the fuse bits.

[tedris]

Thanks What is the difference between these two options?  Which is better?  practical?  Which one can I use?

[madires]

The two-transistor circuit mod requires some soldering and decreases the quiescent current to about 5 µA. Reprogramming the STC15L104W takes less effort but the tester still has a high quiescent current (you could add a switch).

[tedris]

"tester still has a high quiescent current (you could add a switch).
" i dont understand. this Thank you for your help.  How is this a problem for me?  What is the harm?  Is it enough for me to go back to its old self?  I will be careful not to make the same mistake again (testing without discharging the capacitor).

[madires]

With the STC15L104W the tester has a high quiescent current which drains the battery in a few months. To mitigate this you can add a simple switch in series with the battery.