The other night my band played a gig and I set my gear like I always do. Turned on my amp...no sound. played with a few things than got a really weak sound. Worked out there was a bad contact with one of my patch cables from my tuner. Weird thing was that the footswitch wouldnt change channels. FX loop and crunch functions worked but not the channel function. Once I fixed the bad patch cable, everything worked fine. Any ideas?