Capacitor electrolyte or just glue?

[Mooly]

Originally Posted by Reidy-

Hi, thanks for the responses I bought a new tester and you were right it was glue however I found out that these caps were largely out of balance where as one read at 2100uf the other was at 2500uf.

cheers, Reidy-

Sorry to bring bad news but simple capacitor meters that just measure value are of little use in diagnosing problems. As pointed out the tolerance is wide anyway, but the real issue is that cap failure is caused by an increase in ESR.

A good analogy is a 9 volt battery. Whether new or flat, the battery still reads essentially 9 volts off load. What has hapened is that the internal resistance of the battery has increased, and a similar thing happens with electroylitics. You still have a 2200uf or whatever cap, but as it fails it's like a resistor of ever increasing value gets added in series with it.

[musician9]

It's glue, but I would replace them anyway. I would replace them with the largest caps that will fit on the board, maybe 4700u/50v. Always a good idea to go up in value when replacing PS caps, especially in a subwoofer. Also silicone them to the board, as they will be subjected to a lot of vibration.

Dave