On Tue, 15 Dec 2015 07:37:42 -0800, John Robertson
wrote:

I must confess we do replace almost all electrolytic caps that are more
than about 30 years old in our vintage game monitors and amplifiers
(video/pinball/jukebox) as this saves a tremendous amount of
troubleshooting time. It is true that perhaps 60% of the caps replaced
are fine, but the rest are marginal at best and make all sorts of errors
creep in that would take hours to find otherwise.

http://802.11junk.com/jeffl/pics/repair/slides/bad-caps.html
I also do pre-emptive replacements on caps. Worse, if I find a cap
that is bulging or fails an ESR test, I replace *ALL* the caps that
are the same brand and value. Also, if I find a string of parallel
caps, and one is bad, I automatically assume that all of them are
either bad, or will soon fail. That may seem extreme, but I spend
more time extracting and replacing motherboards boards than I do
fixing them. It's easier and cheaper to replace everything that is
suspicious, than to deal with returns, rework, complaining customers,
reputation issues, etc. If the customer returns with the same
problem, but from a different cap, I have to do the rework for free,
which wipes all my profit from the initial repair. Do it right and do
it all the first time.

However, it also helps to pay attention. Do you see a problem here?
http://802.11junk.com/jeffl/crud/GX520-bad-caps.jpg


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558