Last night I plugged a cd player into my gallien Krueger 800rb with a 410 cabinet. It was pretty loud and soon everything stopped working. The head lights up as normal but I cant hear anything. I know this wasnt my best idea and I've already checked the fuse. I cant see any visible break. I'm sure its the head. What could be wrong and how do I fix it? Is it possible that its still the fuse?