trouble with ashdown evo2 300 and trace elliott gp7 amp heads

[trucker glenn]

I am having problems with these two heads. the trace has started making a low but noticable buzz constantly, even with no guitar plugged in. works ok but worried I might harm the amp with farther use. the ashdown isa different affair. it works, well sort of, turn it on and it starts up fine, fans lights, everything looks fine. set your sound set up and the wee needle on the front bounces and peaks like normal, but theres no sound coming through the speakers. I had left this in to get fixed, but it was returned without repair. I looked insided and it looks like two fuses have been removed. the code on there holders is fs2 t10a. at this point im sure yous have all noticed I know sod all bout this sort of thing lol. if I replace these will I get sound???

any help in these matters would be fantastic, and if you can't cheers for reading my post.

trucker:diablo!!