Buzzing sound even without source plugged in.

[Demoninja]

Hey all, I'm back again. I managed to resolve my previous issue with not having audio in one side and the amp worked perfectly for a month or so. Recently the amp started buzzing. Nothing changed as far as I know, it just started out of nowhere. Any recommendations on where to begin troubleshooting?

Edit: So I believe this humming is related to voltages, I had a pair of headphones plugged in and I turned the amp off and the buzzing got noticeably louder until it went away. Before that the buzz would be consistent. I usually have it plugged into a power strip and when I plugged it into the wall directly I heard the buzzing even after the amp was turned off for quite a bit, maybe 2 minutes.

 

[Doc B]

Sounds like a loose ground connection somewhere in the amp. Probably time to go back under the hood and reflow some solder joints.

 

[Grainger49]

There is a sticky for the ground terminations of the Crack.

 

[Demoninja]

Sorry for the delay, I just measured all the ground spots via the sticky that Grainger49 graciously put together. Unfortunately all of them measure out to a solid 0. I'll probably reflow them anyway but if my measurements are accurate then this might not be the problem. I'll edit this post in a few minutes with an update.