Sounds like you may have shorted the output, not a good thing. I have had problems with channels dropping from the amp section myself and feel the same about getting it fixed, it just doesn't seem worth it.

Does the pre-amp section still work? My plan is to add an outboard power amp for the intermittent center channel, and I've been using my tube amp for the left/right channel for a long time anyway, but only for movies. Tv watching is done using center and rears only.