Please help me out - debugging my Ruby Bassman amp

[Rutger]

I just make this my "Help me out!" - topic to prevent this forum from overloading it with topics. 

Last week I blew up my Ruby amp with a reversed 12V adapter pin. It's one of those adapters with different pin-sizes, and I placed it the wrong way so the center became plus instead of minus...  

Anyway, the 100uF cap was blown out and I replaced it. I also replaced the JFET allthough it seemed okay. Checked everything else but didn't find anything broken.

But I don't have any signal yet. I measured the voltages at the pinout of the LM386, everything is fine accept for pint 5 (output). There is a signal but it's only 0,2V instead of 5V.

Does this mean the LM386 is broken or is it something else?

[MarcoMike]

well, that sounds quite reasonble...

[Rutger]

I know.. it's obvious and it looks like the Nr.1 Dumbass Question 2010 (maybe it is).
But i tested it with another LM386 I had lying around, with the same results. But that one is probably dead as well.

[Rutger]

Okay.... plugged in a new LM386 and measured the right voltages. There is a signal now, but it's heavily distorted and it only comes through when I play hard. PLus there are noises when I turn the knobs.

I was thinking, because I reversed the voltage, could it be that the other elco of 200uF is damaged as well? Can I measure it somehow with a simple multimeter?
Or would it be something else?

Sorry for all the dummy questions, but I'm learning a lot from this.