SOLVED: “LCR-T7” tester - reliable?

[eti]

https://www.amazon.co.uk/ARCELI-LCR-T7-Transistor-Tester-Capacitance/dp/B07V688CJP/ref=mp_s_a_1_2?crid=22E68KA5ZFP63&keywords=tc7+tester&qid=1672036747&sprefix=tc7+tester%2Caps%2C73&sr=8-2

I recently saw some info where folk have bought this tester (and the “LCR-T1” variant) and had issues with them failing after a short time - something to do with caps going short.

Any feedback would be helpful before I dive in and get one. Many thanks. Happy Christmas to you! 😃

Update: got me an “Arcelli” LCR-T4 (My favourite version of the tester) for a mere £7.99 with next day Shipping on Amazon Prime, so went for that instead.

[tooki]

All of these testers share the same core design. If it were inherently unreliable we wouldn’t have this insanely long thread about them:

Code: [Select]

eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/(Sorry, the dollar sign in the URL makes it impossible to link to)

[Swainster]

In my experience (of a single T7 version), it has been fine, surviving the last 15 months of light use and a couple of incompletely discharged capacitor accidents without any failures. Of the 3 chinese component testers that I've got, it's still the favourite.

[bffargo]

Beware, with the lack of cheap authentic ATMEL ATMEGA328 chips, in the last 6 months or so more of these clone testers have started putting in clone chips and changing firmware. They may no longer have the same accuracy or even support from the various open source project that started the entire series of these.  See the last many pages of the massive thread: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/8025/

[elecdonia]

Beware, with the lack of cheap authentic ATMEL ATMEGA328 chips, in the last 6 months or so more of these clone testers have started putting in clone chips and changing firmware. They may no longer have the same accuracy or even support from the various open source project that started the entire series of these.  See the last many pages of the massive thread: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/

I agree. I’ve purchased several transistor tester units over the past 5 years. Until about 1 year ago nearly all of them contained Atmel MCU chips, usually the ATmega328.

However, due to price increases and the current scarcity of raw IC chips, a single Atmel ATmega-series MCU chip is now priced higher than a complete transistor tester. Therefore the transistor tester manufacturers have substituted non-Atmel MCU chips which cannot run any of the existing open source software.

The only way to assess “which MCU” is if the vendor provides a photo of the PC board. But few (if any) vendors of these LCR units enclosed in plastic cases show photos of the PC board. Many vendors may not know which MCU is inside the unit they are selling.

For the LCR-TCx and LCR-Tx units I don’t think the TC1, TC2… or the T4, T7… numbering scheme is as meaningful today as it used to be. Several manufacturers now make these units. Their model numbers are often inconsistent with each other.

[elecdonia]

In my experience (of a single T7 version), it has been fine, surviving the last 15 months of light use and a couple of incompletely discharged capacitor accidents without any failures. Of the 3 chinese component testers that I've got, it's still the favourite.

Would it be feasible for you to post a photo of the PC board inside your LCR-T7 so that we could learn what MCU chip is in it?

I’ve been trying to get a LCR-T7 which contains the Atmel ATmega324 MCU. This chip has 44 pins (11 pins on each of its 4 sides). But everything I’ve received so far contains some other incompatible MCU. Some MCU chips were incorrectly labeled (on purpose) or their labels had been sanded off.

[eti]

Does anyone here in England have an LCR-T1 or LCR-T7 with a *genuine* Atmel chip to sell?

[Swainster]

In my experience (of a single T7 version), it has been fine, surviving the last 15 months of light use and a couple of incompletely discharged capacitor accidents without any failures. Of the 3 chinese component testers that I've got, it's still the favourite.

Would it feasible for you to post a photo of the PC board inside your LCR-T7 so that we could learn what MCU chip is in it?

I’ve been trying to get a LCR-T7 which contains the Atmel ATmega324 MCU. This chip has 44 pins (11 pins on each of its 4 sides). But everything I’ve received so far contains some other incompatible MCU. Some MCU chips were incorrectly labeled (on purpose) or their labels had been sanded off.

-E

Had a look inside. There is only one sanded off chip, and it's not the main MCU. That said, the laser etching on the MCU was almost unreadable, though it improved after a wipe with IPA. There was actually some stray solder stuck between a couple of the pins though it wasn't making electrical contact - I removed it just in case it decided to cause problems in the future.

[ledtester]

To embed a link to the transistor tester thread, substitute %24 for the $, e.g.:

https://www.eevblog.com/forum/testgear/%2420-lcr-esr-transistor-checker-project/8025/

will link to reply 8025.

[Swainster]

Oh, I just noticed that my component tester actually says LCR-TC2 on the front. I dont know why I thought it was a T7... though then again it says T7+ on the PCB

[eti]

Does anyone here in England have an LCR-T1 or LCR-T7 with a *genuine* Atmel chip to sell?

Attention!! ^ urgent

[py-bb]

Does anyone here in England have an LCR-T1 or LCR-T7 with a *genuine* Atmel chip to sell?

Attention!! ^ urgent

I really like mine but it did take a while to arrive from China, happy to buy another one if mine's of use:

IC's an APT32F172

I really like it, very useful device, I was skeptical at first because .. well ebay and ships from China right?

As others have noticed the soldering work is sub-par - there's a little spatter on blank areas of the board on mine but it was cheap and very useful and gives consistent readings so I'm happy overall.

[eti]

Does anyone here in England have an LCR-T1 or LCR-T7 with a *genuine* Atmel chip to sell?

Attention!! ^ urgent

I really like mine but it did take a while to arrive from China, happy to buy another one if mine's of use:

IC's an APT32F172

I really like it, very useful device, I was skeptical at first because .. well ebay and ships from China right?

As others have noticed the soldering work is sub-par - there's a little spatter on blank areas of the board on mine but it was cheap and very useful and gives consistent readings so I'm happy overall.

That’s very kind but I’m looking for one with a genuine Atmel IC. What do you want for it?

[Pfriemler]

Bought a LCR-T7 in August 2022 via Amazon. Compared to my two GM328A bad performance, wrong measurements, does not recognize double shottkys and so on. Drift on R measurents -30% within 10 minutes.
Sent it back.

edit: this amazon thing must have been a fake. The "IR feature" did only recognize "Hitachi", others only with a flickering button.
Meanwhile, I have a JOY-IT labeled new one from German reichelt: way better performance, and decodes NEC perfectly.

[py-bb]

Does anyone here in England have an LCR-T1 or LCR-T7 with a *genuine* Atmel chip to sell?

Attention!! ^ urgent

I really like mine but it did take a while to arrive from China, happy to buy another one if mine's of use:

IC's an APT32F172

I really like it, very useful device, I was skeptical at first because .. well ebay and ships from China right?

As others have noticed the soldering work is sub-par - there's a little spatter on blank areas of the board on mine but it was cheap and very useful and gives consistent readings so I'm happy overall.

That’s very kind but I’m looking for one with a genuine Atmel IC. What do you want for it?

Enough to cover P&P and the cost of a new one and I'm happy. As long as I'm not out of pocket.

It's basically brand new, it arrived on the 23rd (it took a while obviously from China), but as I'm UK also you'd get it much quicker. They're better than you'd think and I fully intend to replace it if you do buy it from me. I just don't mind waiting for a replacement.

[eti]

Does anyone here in England have an LCR-T1 or LCR-T7 with a *genuine* Atmel chip to sell?

Attention!! ^ urgent

I really like mine but it did take a while to arrive from China, happy to buy another one if mine's of use:

IC's an APT32F172

I really like it, very useful device, I was skeptical at first because .. well ebay and ships from China right?

As others have noticed the soldering work is sub-par - there's a little spatter on blank areas of the board on mine but it was cheap and very useful and gives consistent readings so I'm happy overall.

That’s very kind but I’m looking for one with a genuine Atmel IC. What do you want for it?

Enough to cover P&P and the cost of a new one and I'm happy. As long as I'm not out of pocket.

It's basically brand new, it arrived on the 23rd (it took a while obviously from China), but as I'm UK also you'd get it much quicker. They're better than you'd think and I fully intend to replace it if you do buy it from me. I just don't mind waiting for a replacement.

I appreciate it very much, but times are tight for now. I think I’ll wait it out for an Atmel-based model. Thanks so much for the offer though. Happy 2023! God bless you.

[elecdonia]

In my experience (of a single T7 version), it has been fine…

…Had a look inside

Thanks for the PC board photos of your LCR-T7. Your unit contains a genuine Atmel ATmega324 MCU. This is confirmed by the MCU chip having 11 pins on each side, 44 pins total. This 44 pin package is unique to the Atmel MCU chip family which includes the ATmega324 and the ATmega644 .

The other Atmel MCU chip frequently used in transistor testers ( ATmega328 ) has 8 pins on each side, 32 pins total.

To the best of my knowledge all of the alternate Chinese MCU chips recently showing up in transistor testers also have 32 pins. Some are (deliberately) mislabeled as ATmega328. However their pinout and internal functionality is completely different.
 
The Chinese manufacturers have cobbled together their own proprietary firmware. Its quality varies:
   1) Usually several of the expected transistor tester features are missing
   2) Some measurement results may be very inaccurate
   3) It is impossible to upgrade or replace this proprietary firmware

At this time none of the extensive library of open-source transistor tester software/firmware supports any of these alternative Chinese MCU chips.

[elecdonia]

Oh, I just noticed that my component tester actually says LCR-TC2 on the front. I dont know why I thought it was a T7... though then again it says T7+ on the PCB

The LCR- model number suffixes ( TC1, TC2, T7, T7+, etc.) printed on the outer case of these units seem to be randomly interchangeable. I haven’t yet determined whether the internal labeling on their PC boards is meaningful.

[py-bb]

Oh, I just noticed that my component tester actually says LCR-TC2 on the front. I dont know why I thought it was a T7... though then again it says T7+ on the PCB

The LCR- model numbers ( TC1, TC2, T7, T7+, etc.) printed on the outer case of these units seem to be randomly interchangeable. I haven’t yet determined whether the labeling on the internal PC boards is meaningful.

-E

When I was buying one I was wondering about that, the specifications given on ebay listings are very poor, I decided based on pictures of things shown measured. The specs are also wrong like the one I have is supposed to top out at measuring 5Mohm, it measured 9.7 earlier.

I've also found that it'll measure certain features only between certain ports, so say 1 and 3 is generally better (measures more) than 1 and 2.

I'll take some pictures of mine soon - it can't hurt.


That said I really like it. It's unusual in that it's a better product than the listings imply.

[elecdonia]

When I was buying one I was wondering about that, the specifications given on ebay listings are very poor, I decided based on pictures of things shown measured. The specs are also wrong like the one I have is supposed to top out at measuring 5Mohm, it measured 9.7 earlier.
I've also found that it'll measure certain features only between certain ports, so say 1 and 3 is generally better (measures more) than 1 and 2.
I'll take some pictures of mine soon - it can't hurt.

When you get different results testing the same resistor (or capacitor) on different ports of the transistor tester (such as 1-2, 2-3, or 1-3) this means you need to perform the "self calibration" procedure. To do this you first need to assemble 3 very short wires (< 2 inches) twisted or soldered together. Then place them into the ZIP socket on the tester to short out all three port pins at the same time (1, 2, and 3). Next press power button on tester. Display should be "selftest." After some time passes it will display "isolate probes." Now remove the shorting wires. Selftest will continue and eventually the tester will shut off. Next time you test a resistor (or capacitor) the result should be nearly identical no matter which set of test ports (1-3, 1-2, or 2-3) the component is connected to.

Note: Inductors and some other 2-wire components may require using ports 1 and 3 to test.

[py-bb]

When I was buying one I was wondering about that, the specifications given on ebay listings are very poor, I decided based on pictures of things shown measured. The specs are also wrong like the one I have is supposed to top out at measuring 5Mohm, it measured 9.7 earlier.
I've also found that it'll measure certain features only between certain ports, so say 1 and 3 is generally better (measures more) than 1 and 2.
I'll take some pictures of mine soon - it can't hurt.

When you get different results testing the same resistor (or capacitor) on different ports of the transistor tester (such as 1-2, 2-3, or 1-3) this means you need to perform the "self calibration" procedure. To do this you first need to assemble 3 very short wires (< 2 inches) twisted or soldered together. Then place them into the ZIP socket on the tester to short out all three port pins at the same time (1, 2, and 3). Next press power button on tester. Display should be "selftest." After some time passes it will display "isolate probes." Now remove the shorting wires. Selftest will continue and eventually the tester will shut off. Next time you test a resistor (or capacitor) the result should be nearly identical no matter which set of test ports (1-3, 1-2, or 2-3) the component is connected to.

Note: Inductors and some other 2-wire components may require using ports 1 and 3 to test.

-E

Not what I meant, I meant like say we put a capacitor between 1 and 3, you'll get an ESR and a drop %age out of it as well as a capacitance, put the same capacitor on 1 and 2 and you get just capacitance.

"" for diodes (but different readings)

[indman]

I recently saw some info where folk have bought this tester (and the “LCR-T1” variant) and had issues with them failing after a short time - something to do with caps going short.

Hi! Why create duplication and many topics for discussing the same device, if there is a global topic where this project is discussed and one of the respected authors madires participates? In this way, you are spraying valuable information that would be useful to other people.And so you have to jump from one branch to another, instead of just using a search service that normally works on the forum.

[eti]

I recently saw some info where folk have bought this tester (and the “LCR-T1” variant) and had issues with them failing after a short time - something to do with caps going short.

Hi! Why create duplication and many topics for discussing the same device, if there is a global topic where this project is discussed and one of the respected authors madires participates? In this way, you are spraying valuable information that would be useful to other people.And so you have to jump from one branch to another, instead of just using a search service that normally works on the forum.

Good point. Thanks. Happy 2023! Thanks for your hard work. It’s appreciated.

[elecdonia]

I've also found that it'll measure certain features only between certain ports, so say 1 and 3 is generally better (measures more) than 1 and 2.

When you get different results testing the same resistor (or capacitor) on different ports of the transistor tester (such as 1-2, 2-3, or 1-3) this means you need to perform the "self calibration" procedure. Note: Inductors and some other 2-wire components may require using ports 1 and 3 to test.

Not what I meant, I meant like say we put a capacitor between 1 and 3, you'll get an ESR and a drop %age out of it as well as a capacitance, put the same capacitor on 1 and 2 and you get just capacitance

Yes, there are enhanced measurement features for capacitors and inductors. These function only with ports 1-3. Availability of these features depends on which firmware is in the tester. I need to re-read the official transistor tester documentation again - I know these enhanced features exist but I haven’t yet studied them in depth.

[py-bb]

I've also found that it'll measure certain features only between certain ports, so say 1 and 3 is generally better (measures more) than 1 and 2.

When you get different results testing the same resistor (or capacitor) on different ports of the transistor tester (such as 1-2, 2-3, or 1-3) this means you need to perform the "self calibration" procedure. Note: Inductors and some other 2-wire components may require using ports 1 and 3 to test.

Not what I meant, I meant like say we put a capacitor between 1 and 3, you'll get an ESR and a drop %age out of it as well as a capacitance, put the same capacitor on 1 and 2 and you get just capacitance

Yes, there are enhanced measurement features for capacitors and inductors. These function only with ports 1-3. Availability of these features depends on which firmware is in the tester. I need to re-read the official transistor tester documentation again - I know these enhanced features exist but I haven’t yet studied them in depth.

Whoa whoa whoa: you found a manual? - I got nothing with mine. I had to discover the 1-3 port thing!

BTW mine says T7 but if I do that firmware trick (press power button 4 times - I needed to unplug the battery to get it out of "bootloader mode") it says TC1 bootloader!

Also mine has wrong specs, ebay's listing said it could measure up to 5Mohm - I've tested 9.4Mohm just fine - I've not seen how high it can go.

Share the manual!