$20 LCR ESR Transistor checker project

[Fuzzy Star]

Like to change 'fake' Chinese IC part for genuine "Mega328P U-TH" on device "LCR-T4"   = possible?

See these posts:
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4762751/#msg4762751
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4745147/#msg4745147
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4742351/#msg4742351

[Stinger]

Hi,

Can i flash these LCR-T4 V2.68 clone with CH341a USB programmer ?

[madires]

Yes, if your CH341a USB programmer supports ISP.

[morgan_flint]

I bought a GM328A tester from AliExpress ...
Anyone has a working English flash, hex file for this latest version tester?

I also bought one of these "new version" of GM328A to add to my collection (my TEA is severe...). If the FW posted by indiman doesn't fit, I can try to make a backup of mine, which is in English, if it's not protected.

Also, @indiman, I see this version is not in your table of clones; if you want to include it and need more details, I'd be happy to contribute. It seems genuine 328P for <14€, and I bought it also because, form the photos in the ad, it seemed to have a DC/DC converter that I thought was for zener measurement (but I think it's not) and something that seemed a prescaler for frequency (also think it's not, but up to now I haven't analised it too much).

[Circlotron]

Haven’t read the whole thread, it’s a bit long. Got one of these things yesterday and every electrolytic cap I measure it shows ESR as zero ohms. Am I doing something wrong or are some of these testers a bit dodgy?

[madires]

Have you done the self-adjustment?

[Circlotron]

Have you done the self-adjustment?

No. It did not come with any instructions. Where could I find these?

[madires]

Short-circuiting all three testpins should trigger the self-adjustment. I don't know if there's a manual for the T4 clone, but please see Karl-Heinz' documentation for the k-firmware (https://github.com/kubi48/TransistorTester-documentation).

[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 ?

https://www.aliexpress.com/item/1005005237553083.html?spm=a2g0o.productlist.main.3.3fc517ecauDpV2&algo_pvid=f153996f-afd1-4412-bd4a-b646f44233fb&algo_exp_id=f153996f-afd1-4412-bd4a-b646f44233fb-1&pdp_npi=4%40dis%21AUD%2154.17%2119.51%21%21%2133.88%21%21%402103228816963420811975338e03f6%2112000032317691182%21sea%21AU%211614096062%21&curPageLogUid=GZo8cWxUPCuz

https://www.aliexpress.com/item/1005005430295628.html?spm=a2g0o.productlist.main.1.3fc517ecauDpV2&algo_pvid=f153996f-afd1-4412-bd4a-b646f44233fb&algo_exp_id=f153996f-afd1-4412-bd4a-b646f44233fb-0&pdp_npi=4%40dis%21AUD%2142.75%2121.37%21%21%21195.72%21%21%402103228816963420811975338e03f6%2112000033040265575%21sea%21AU%211614096062%21&curPageLogUid=7Wh4HQxFGkdT

[madires]

Make sure to choose a clone with a genuine ATmega. Currently many clones are sold with APT32F172K8T6 or LGT8F328.

[LeWidget]

Make sure to choose a clone with a genuine ATmega. Currently many clones are sold with APT32F172K8T6 or LGT8F328.

How do you find that out? Reading the description of the products does't mention anything about what chip they come with :/

[lezginka_kabardinka]

Make sure to choose a clone with a genuine ATmega. Currently many clones are sold with APT32F172K8T6 or LGT8F328.

You make it sound like "a choice" 

[madires]

How do you find that out? Reading the description of the products does't mention anything about what chip they come with :/

It's a lottery at the moment, but there are some hints:

We have seen popular clones sold in multiple variants with genuine ATmegas and
alternative MCUs, some even with fake ATmega markings. When buying a clone it
can be hard to identify the MCU. Some hints:
- MCU in DIP is usually an genuine ATmega.
- APT32F172K8T6 has different power pins:
  - 32-LQFP/QFN: 18=Vss, 19=Vdd (ATmega328 32-TQFP: 5=Gnd, 4=Vcc)
- APT32F172K8T6 uses SWD port for ISP:
  - 5 pins: Vdd, Vcc, F_SDAT, F_SCLK, F_RST
- Testers with APT32F172K8T6 often lack a quartz crystal.
- LGT8F328 has slightly different pins:
  - QFP32L: 21=PE2/SWD (ATmega328 32-TQFP: 21=Gnd)
- LGT8F328 uses SWD port for ISP:
  - 5 pins: Gnd, Vcc, SWD, SWC, Reset
- Clone variants with an genuine ATmega are usually about EUR/US$ 5 more
  expensive than the variant with a different MCU.

Your best bet is to look for an DIP ATmega or to build a tester yourself.

[Aldo22]

I think the slightly more expensive here could be "genuine".
The version called "English Language" (DIP), not the "New English Version".
It's hard to tell with the versions with a case.

[LeWidget]

Thanks for the info . Q: what does DIP mean ?

[Aldo22]

Thanks for the info . Q: what does DIP mean ?

https://en.wikipedia.org/wiki/Dual_in-line_package

[Messtechniker]

Your best bet is to look for an DIP ATmega or to build a tester yourself.

Prefably socketed in case you fry your chip with a charged capacitor.

[TA2AWX]

Now, this is an interesting video, I timestamped it to the point about counterfeits, but the whole thing is a good watch.

https://youtu.be/wjEI6d8MEJE?si=YFvrNjc8KSCe9m3H&t=546

[madires]

Interestingly, TheElectroBench said in his video that later versions of the LCR-TC2 support around 15 IR RC protocols. What a coincidence! It would be nice if the Chinese clone manufacturers would adhere to the m-firmware's open source license.

[morgan_flint]

I think the slightly more expensive here could be "genuine".
The version called "English Language" (DIP), not the "New English Version".
It's hard to tell with the versions with a case.

As I said here, I also bought one of these in the "New English Version" with the MCU in TQFP-32 package; I've checked the pinout according to madires' tips here and it seems to be a genuine Atmega. The ICSP pads also go to the correct pins according to ATmega328p's pinout.

Still haven't tried to read the FW, though.

[Ariamella]

Is there a version of this with an STM32 chip or something along those lines? STM32 MCUs are significantly cheaper nowadays...

[madires]

The Transistortester needs a 5V MCU to keep the circuit simple.

[Lazarus42]

Hey everyone, how's stuff?
Well, an LCR-T4 ESR has just arrived. After much trolling around I plumped for the  one in the photos.
As a bit of a noob I had no idea of the can of worms I was opening. This thread has been fascinating and a steep learning curve for me as I'm just starting out with electronics.
I'm also starting RC slope soaring, I bought the glider after I ended up on two prosthetic legs as incentive to get up & outside.
I thought that apart from being interested in both they seem to dovetail together.
So! how'd I do? Does anyone recognise the beasty that just arrived?
I haven't turned it on yet as my rechargeable 9V battery is not putting out 9V even at full charge, 8.2V isn't in spec and I've read in here that accuracy is sensitive to voltage.
Thanks for this thread, it's been interesting, funny and quite a bit of "Oh bu**er!
Keep safe all,
Lazarus 😎☮️
Edit: Aargh! Just realised, no crystal! ☹️

[madires]

Yep, fake 328. A genuine 32pin TQFP ATmega328 would have pin 21 (Gnd) connected to ground and pin 20 (AREF) to a 1nF cap. Don't worry too much about the battery's voltage as long as it's above 7V.

[Lazarus42]

Thank you! That's eased the pain a little 😃
I'm on the hunt for a manual at the mo and acrylic case on the way.
Onwards and upwards!

Laz😎