Fillmore Silence

My Fillmore 25 combo stopped making a sound between songs. It was still on, so no blown fuse.... It just stopped making sound. I plugged directly into the amp to eliminate board issues, and... no sound. No burning smell, the speaker was still connected... We just finished a tune, and as we started another the amp simply didn't make a sound.

I'm going to check tubes tomorrow (later today, actually)... but I'm flummoxed. Anyone else have anything similar happen?

I haven't had an amp suddenly cut out completely due to preamp or power tubes, but it does happen and that'd be the first thing I'd check. How old are the tubes?

Are there any Fillmores old enough to not still be under warranty?

Good luck and please keep us up to date on how it goes.