A few weeks ago during rehearsal, I noticed that I could not hear one of my guitars through the headphones. The odd thing is that I can hear him until I solo his channel, then the headphones go silent. As we continued rehearsal, I noticed several other channels (both vocal and instruments) started doing the same thing. Last night I could hear the mix through the headphones, but each time I tried to solo a channel all went quiet. I don't know of anything specifically that I changed to cause this. I don't know if this is related, but we had moved several mics around the Sunday before and were having problems getting them back into the correct place. We ended up going to a scene we had saved before the move and starting over. I thought this may fix my soloing channel problem as well, but it didn't. I'm totally lost and would appreciate any help you can offer. Thanks.