$20 LCR ESR Transistor checker project

[phantom]

i know this is a stupid question...but 399 pages are too much for me to find the answer!

i 've bough 4 years ago a tcr-t7h...never used...should i update the firmware? should i do some "hardware mods"?

how? thanks

[indman]

phantom
https://github.com/madires/Transistortester-Warehouse/blob/master/Documentation/English/Mini-FAQ.indman.pdf

[Feliciano]

@snapper:
Yes, something like that. And for the software you can use WinAVR with the proper toolchain. On the FAQs made by indman and me you can find more information.

[proditaki]

I've been reading this topic since my LCR-TC1 died.  (the controller is dead)

From the clone comparison i've gather that my model has the LGT8F328 controller.

The comparison doesn't mention upgrading it to an Atmel processor, but reading the forum makes me think it's possible.
I have some AtMega328p lying around, but i'm a bit confused about what to do.

From what i've read here you can replace the LGT8F328 with the ATMega328p but not without some adjustments.
But it's not exactly clear to me what adjustments are needed.

Can anybody help me out?
For clarity i added some pictures.

[pupkinv]

This way
https://4pda.to/forum/index.php?showtopic=948444&st=5640#entry124389340

[proditaki]

This way
https://4pda.to/forum/index.php?showtopic=948444&st=5640#entry124389340

Thanks a lot, the firmware link in the post doesn't work. Is there an alternative ? 

[pupkinv]

Thanks a lot, the firmware link in the post doesn't work. Is there an alternative ? 

Downloads only for registered users.

[indman]

proditaki ,This firmware is in Russian. You can get the firmware in English from this post
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4899587/#msg4899587

[CaptainBucko]

From what i've read here you can replace the LGT8F328 with the ATMega328p but not without some adjustments.
But it's not exactly clear to me what adjustments are needed.

With a few minor PCB modifications, you can replace the LGT8F328 with the ATMega and add an ISP header as shown in the photos. This is small enough (in height) so you can still reassemble the unit in the factory case.

[proditaki]

I followed the instructions

Now it always gives me this.

[madires]

The tester sees a permament voltage on probe #3.

[proditaki]

Its weird.
I double checked all connections

I dont see /measure anything wrong

[madires]

Is D2 (SRV05-4, over-voltage protection) damaged? Please try again with D2 removed. When the MCU is toasted by a charged cap D2 is often toasted too.

[proditaki]

Is D2 (SRV05-4, over-voltage protection) damaged? Please try again with D2 removed. When the MCU is toasted by a charged cap D2 is often toasted too.

I get the same result with D2 removed, so i'm guessing that's not it

[madires]

Could you please take a DMM and measure the voltage at the ADC pin of probe/testpin #3 while the tester shows the error message?

[proditaki]

Could you please take a DMM and measure the voltage at the ADC pin of probe/testpin #3 while the tester shows the error message?

It's 7.2mv it's measuring.

[madires]

We're missing something.

[proditaki]

We're missing something.

Yeah, it's very weird.
I got the error message you get when nothing is connected once or twice, but then the same reading on pin 3 again.

[indman]

proditaki You need to make changes that are shown in the diagram in red. The tesa of these additions the tester will not work normally.
C32 does not have to install, the tester will work normally without this capacitor.

[proditaki]

proditaki You need to make changes that are shown in the diagram in red. The tesa of these additions the tester will not work normally.
C32 does not have to install, the tester will work normally without this capacitor.

i added C31. The other mods i already had made. sadly it's still not working properly, same error

[indman]

Contact 3 and 5 of the controller did you connect together?

[proditaki]

Contact 3 and 5 of the controller did you connect together?

Yes i checked with the multimeter as well.

[indman]

Contact 3 and 5 of the controller did you connect together?

Yes i checked with the multimeter as well.

I do not see in the photo that you showed before this jumper.

[proditaki]

Contact 3 and 5 of the controller did you connect together?

Yes i checked with the multimeter as well.

I do not see in the photo that you showed before this jumper.

[indman]

proditaki, I can see the jumper now. But I also see that you have a lot of flux residue and dirt on the board.Remove them and also very carefully clean the ZIF panel contacts.If the problem does not disappear, we will think further how to solve it.