I can't help much, but I learned this trick a while back to figure out if the problem is in the pre-amp section or the power-amp section.

I'm not familiar with that amp, but if it has an effects loop, plug your guitar straight into the return of the loop instead of the main input (don't plug anything into the send). This bypasses the pre-amp section. If you get sound then the problem is in the pre-amp section....If you don't get sound, the problem is most likely in the power-amp section of the amp, but could be both.

I'd recommend taking it to get checked out by a pro though.