Erratic ESR Readings on Antek Blue ESR Meter

[SgtRock]

Greetings BadCappers:

--I have a question about Capacitors and ESR. I am using an Anatek Blue ESR Meter to measure the ESR of a bunch of caps in a RCA DTA809 TV Converter. I measure the Capacitance and ESR in circuit and then I measure the same out of circuit, keeping careful track of the measurements, specs, location and size of the caps.

--Most of the caps show a rock steady ESR. But, on some the ESR measurement jumps around both in and out of the PCB. But it never gets so high as to fail the cap for ESR. I have a 10 V 470 uF, and the ESR jumps around between 0.10 to 0.40 Ohms erratically. Please tell me that this cap is bad. I have another one, 16V 220 uF that only jumps around between 0.39 to 0.43 Ohms, that I am even less sure about. None of the caps are bulged or abnormal looking in any way.

--This converter had the blinking light, and would not turn on. Temporarily, I was able to get a steady light and turn on, by warming the caps gently with a heat gun, so I am pretty sure I have a cap problem. I plan to replace them all. But, I am hoping that someone with more experience than I, will comment on the erratic ESR.

"An expert is a man who has made all the mistakes which can be made in a very narrow field."
Niels Bohr 1885 - 1962

Best Regards
Clear Ether

[tom66]

Re: Erratic ESR Readings on Antek Blue ESR Meter

Both of those caps are suspect, they should measure less than 0.04 ohms in my opinion.

Shame that the US government didn't insist on a minimum 10 year warranty on these items, after all, most were given to unaware people under the converter box scheme, and they are rapidly dying. Just built to fail...

[SgtRock]

Re: Erratic ESR Readings on Antek Blue ESR Meter

Dear Tom:

--In saying they had not reached the fail point, I was going by the diagram that came with the Anatek meter. I know from looking at the other caps that these started out life below 0.10 Ohms ESR, so I agree with you they are hinky.

--Hypothetical question: What if the same caps had a ESR jumping around erratically between 0.10 to 33 Ohms? Or say between, 25 and 30. I am used to the ESR moving a last digit or two? But I am talking about moving around erratically 5 digits or more. Can I use that as a failure check mark? As usual I appreciate being able to pick your brain, or anyone's for that matter. Thanks.

"Measure twice. Cut once"
Norm Abram 1950 -

Best Regards
Clear Ether

[tom66]

Re: Erratic ESR Readings on Antek Blue ESR Meter

A cap should hold a particular ESR; if the reading is that erratic, then I'd consider the probes or meter to be at fault. Try cleaning probes and zeroing meter.

[SgtRock]

Re: Erratic ESR Readings on Antek Blue ESR Meter

Dear Tom:

-- As I said at the beginning of this post. "Most of the caps show a rock steady ESR. But, on some the ESR measurement jumps around both in and out of the PCB." Tai'nt the probes.

"He didn't know where he was going. But he knew where he was wasn't it."
Lord Buckley 1906 - 1960

Best Regards
Clear Ether

[tom66]

Re: Erratic ESR Readings on Antek Blue ESR Meter

Very odd- perhaps the leads of the suspects are contaminated or dirty?