Hi everyone.  I bought a used Roland KC-300 (Edit this is a Roland KC-350) keyboard amp a while ago and it worked great for a while.  One day I was plugging in a patch cable while the amp was on and it blew something.  The volume was barely audible and it was crackling from both the tweeter and the main speaker.  It was like a really bad distortion and really low volume.

I ended up taking it to an amp repair shop and they fixed it for 100$.  I don' think they really had to change any major parts but they didn't really explain to me what they fixed.

So lesson learned no to plug in anything while the amp is on.  But I was having some people over to jam and one of them did the same thing and now I am faced with the same issue.

I don't want to take it back to get repaired again for 100$, I only paid 150$ for it.  This time I would like to take a crack at fixing it myself first but I don't know where to start.  I removed the 12 inch speaker and had a look for any exploding or leaking caps but didn't see any.

If it helps, it has this issue only when driving the speakers, when I hook up headphones the sound is clear.

Any help would be greatly appreciated!  :tu: