Quote:
Originally Posted by leka4
Thanks for your post, but what you are stating, although true, is only half of the story. Based on my research of this topic after your post, there is no accurate way to test a capacitor while it is in-circuit on the board. ESR meters are good tools, but if you are wanting to know with 100.00% certainty that all capacitors on a board don't have any issues (which it sounds like you do) and visual and functional tests are not satisfactory to you, the only true option is to physically yank each and every one of the scores of capacitors from the boards, test it outside the board, then re-solder it back in. At that point, I am not sure why one would even test the caps, as they cost almost nothing material wise to replace. If accuracy of tests, and complete peace of mind is your goal, I am not sure what an ESR will accomplish in-circuit...
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I didnt claim to be telling the whole story. ESR testing in situ often gives
more of the story than just looking for bulging or expelled electrolyte. Often but not always the ESR and capacitance of such electrolytics can be tested in situ. Sometimes not, depending on the circuit in which the cap operates, in which case the capacitor needs to be unsoldered and removed for full testing.
You raised the issue of capacitors, not me. I was comparing mere visual inspection, with visual inspection plus ESR testing. I wasnt claiming to write a full treatise on the subject as you seemed to imply I was.
As the old saying goes, it's good to avoid "making the perfect (the 100%) the enemy of the good".
I wish you well and hope you sell your VCR, and all parties are satisfied.
