#1
I've got a Bugera 1990 that I've had since December (so, 7 and a half months or so?) and today I was playing it and the sound decrescendo'd (faded out) until it was nothing.

Is it the tubes? If not, what else would it be?
#4
No, if it was the fuse, the lights would have gone out, wouldn't they? It sounds like the tubes to me, I just wanted a second opinion before I took it to the local store.