In-circuit ESR meter recommendation?

[ASDR]

Right now I'm still using one of those transistor testers as my LCR meter and for ESR measurements. Seems to give plausible readings if you don't use test leads and put the capacitor directly in the ZIF connector. But I'd like to buy a decent ESR meter that can also test capacitors in-circuit. I'd consider buying a full LCR meter if that doesn't cost too much. I don't really want to spend hundreds on fancy test gear, but I don't know if any of the cheaper stuff on AliExpress is actually usable.

Can you recommend a 'good enough' in-circuit ESR meter or maybe some full-blown LCR meter with ESR/ESI readout if it isn't significantly more expensive?

Thanks!

[tongshadow]

ESR02 PRO.

[Syntax]

Atlas ESR70 with a set of tweezer leads.

[ASDR]

ESR02 PRO.

I have two of those cheap transistor testers that also do LCR and ESR duty and that looks like one of them in a fancier case. Like I said they seem to work OK without leads. IIRC there was some calibration mode where I could zero out the effect of the test leads, maybe I should have another look at those before spending money.

Atlas ESR70 with a set of tweezer leads.

Yes, I've seen that one before in a couple of videos! That should do it, like ~115 eurodollars. Why do you recommend the tweezer type test lead? Just more convenient that the crocodile clips?

[matt]

I have one of the Atlas testers. I haven't had too much success testing in circuit. Usually I desolder one leg of each cap I want to test, which is still faster than pulling them all.

[ASDR]

I have one of the Atlas testers. I haven't had too much success testing in circuit. Usually I desolder one leg of each cap I want to test, which is still faster than pulling them all.

Well that's disappointing to hear. Since most electrolytics either sit fairly flush or are SMD I don't really see how I could just desolder a single leg and at that point I might as well just replace everything. Is there a pattern to when it does and doesn't work? Like capacity or the circuit, like if you have several caps parallel to lower ESR/increase capacity?

[Syntax]

Yes, I've seen that one before in a couple of videos! That should do it, like ~115 eurodollars. Why do you recommend the tweezer type test lead? Just more convenient that the crocodile clips?

The tweezers make checking everything in circuit fast, then the stuff that failed to test in circuit you can pull a leg and test.

Testing in circuit is hit and miss.

[ASDR]

Yes, I've seen that one before in a couple of videos! That should do it, like ~115 eurodollars. Why do you recommend the tweezer type test lead? Just more convenient that the crocodile clips?

The tweezers make checking everything in circuit fast, then the stuff that failed to test in circuit you can pull a leg and test.

Testing in circuit is hit and miss.

Does the in-circuit measurement fail on certain types of capacitors or is it mostly about the placement in the circuit? When it fails, what happens? Does the device show an error or is there simply an implausible ESR reading?

[Syntax]

Its a mixed bag.

Say you have caps in parallel on the circuit, it will add them and give you that reading, making you think that the cap is reading way over and stuffed.

Most of the time it will yell "In circuit/Leaky" if there is an issue.

[ASDR]

Doesn't sound too encouraging what you and matt are saying. I don't really see how I can just desolder one leg. Most of the prone-to-fail caps are on the bigger side, and they are generally sitting flush on the board, so I can't just pull out one leg. Also once I have the desoldering gun out desoldering both legs takes like a second longer and then I might as well just put in a new capacitor. I think instead of the meter I'll just buy 115EUR worth of JPN capacitors

[tongshadow]

Every electrolytic capacitor I tested in circuit with the equipment I mentioned has also returned nearly the same ESR values when removed.

[viletim]

I used an ESR meter for years. It's very useful for checking electro caps in older equipment, measured in circuit. The ESR meter got daily use, but the LC meter sat in a drawer most of the time and got pulled out a couple of times a month.

The one I used was the Bob Parker ESR meter. I would recommend that one if you can find it. It has a large LED display that updated very quickly, faster than most multimeters. I found that probe quality was very important. The probes need to be sharp (to pierce the oxide layer) and have lots of copper inside for a good low resistance connection. Otherwise the ESR will appear to change as you move the probes.

[matt]

Doesn't sound too encouraging what you and matt are saying. I don't really see how I can just desolder one leg. Most of the prone-to-fail caps are on the bigger side, and they are generally sitting flush on the board, so I can't just pull out one leg. Also once I have the desoldering gun out desoldering both legs takes like a second longer and then I might as well just put in a new capacitor. I think instead of the meter I'll just buy 115EUR worth of JPN capacitors

I mostly use it on CRT TVs and monitors with single sided PCBs. It's easy to desolder one leg of all the "problem" capacitors from the back and, when testing, position it so that it loses contact with the sides of the hole. Afterwards if everything tests OK, resoldering everything is pretty quick. For me, this is faster than removing the suspect caps, testing them, and putting in replacements. This wouldn't work on plated-through holes, though.

[ASDR]

Doesn't sound too encouraging what you and matt are saying. I don't really see how I can just desolder one leg. Most of the prone-to-fail caps are on the bigger side, and they are generally sitting flush on the board, so I can't just pull out one leg. Also once I have the desoldering gun out desoldering both legs takes like a second longer and then I might as well just put in a new capacitor. I think instead of the meter I'll just buy 115EUR worth of JPN capacitors

I mostly use it on CRT TVs and monitors with single sided PCBs. It's easy to desolder one leg of all the "problem" capacitors from the back and, when testing, position it so that it loses contact with the sides of the hole. Afterwards if everything tests OK, resoldering everything is pretty quick. For me, this is faster than removing the suspect caps, testing them, and putting in replacements. This wouldn't work on plated-through holes, though.

That's a good point, lot's of TVs have single-sided boards and it's quite common for power supplies as well.

The one I used was the Bob Parker ESR meter.

I've seen that one in an EEVBlog video, but I have no idea where to get one :/ I think it was mentioned in the video it was sold as a kit?