Car Stereos: Car amplifier one channel is acting up, car stereo installations, car amplifier

Question
QUESTION: From you description i don't know if you can answer this or
not but here goes. I recently bought an Actiway 400x2
amplifier from a friend for 30 bucks and the right channel
works perfectly. The left channel on the other hand when i
hook a sub up to it as soon as i add power (this even with
no input plugged in from the radio) the sub almost bottoms
out and shutters and pops continuously until i remove the
power. I've removed the cover and did a cursory check of
the inside there seems to be no shorted out parts and the
negative side of the left channel works so i think i have
it narrowed down to just the positive terminal on the left
channel. I cant seem to find any thing wrong and it is
getting power. Any help would be greatly appreciated.

Thanks in advance

ANSWER: Hi Jason,

The positive is where all the power comes from. :)  Unfortunately, that side is likely shot and need electrical components replaced before it will work again.

Justin

---------- FOLLOW-UP ----------

QUESTION: one more question could you tell me what kind of tools other than something to test for continuity i could possibly need to diagnose a problem cause i figured id need to replace some parts and ive done alot of soldering so i know how to replace them. Also any idea on what could be a general problem that youve mabey seen before.

Thanks again

Answer
Hi Jason,

This goes a little beyond the scope of car stereo installations, but outside of the replacement coponents, all you should need are a good multimeter to test the components.

The most common scenario in blown amps is overheating frying components.  Look for capacitors that have expanded (and possibly even blown up), solder joints that've gone bad from melting away, and leaking crystals.

Justin