It's a bit early to talk about trashing it. Are you getting a power on light? If not, then it almost has to be a fuse.
If you have the light, but no sound, take a cord and plug it into the preamp out. Run the other end to another amp. A power amp or the power amp in would be best, but you're just looking to see if there's any signal at all, right? See if you're getting a signal from the preamp out.
If not, do the opposite, and see if you're getting an output from the power amp. Plug into the Power Amp In on the back with a signal of some kind, be it the preamp out from another amp, a CD player, whatever. Keep the input level low. Remember, you're going to be getting the full gain of the power amp when you do this. If you don't hear anything, turn the signal up slowly.
What all this does is to isolate the problem to either the preamp or the power amp section. That's enough for now.