How do I test for a faulty electrolytic capacitor in the power supply of my Crate guitar amplifier????

Question

How do I test for a faulty electrolytic capacitor in the power supply of my Crate guitar amplifier????

Answer 1

Just take it to Dr. Brown,  Marty

Answer 2

This can be rather easy, in many cases.  

Electrolytic capacitors have a PVC shrink-tube plastic cover to shield the aluminum case from other devices, as the case is tied to the negative terminal.  When many electrolytics start to fail they heat up.  The heating causes the shrink tube to shrink even more, and instead of covering much of the end, it pulls away and can even leave the end of the capacitor exposed totally.  Replace any that have this indicator whether or not they have failed yet.

But the easiest way to solve the problem is the shotgun approach- replace them all!  They are cheap (mouser.com) and there are only a few big ones, anyway.  Since they are the weak point of any circuit board, as they are the workhorse of a circuit, it is good to replace them anyway on an old system.  It will give the circuit board new life.  They will fail over time...

Answer 3

If the capacitor has failed it may just be because of a bad connection. Have a look at all the solder cnnections on all the capacitors and look for a dull looking solder, one which is not shiney like the rest. If you find one this may need re-soldering.

As this is a power supply capacitor and you are not sure what you are doing I suggest leaving it to a professional as capacitors even when not connected to the power can contain dangerous stored electricity which might be several thousand volts.