I just bought a used H&K switchblade 100 combo a few days ago. Fantastic amp, everything was running great until today when i turned it on and found that the MIDI footswitch no longer switched between presets. When i pressed a button to change the channel, it did nothing, almost like the entire presets were wiped out. So i tried to restore them however, when i went to store them it wouldnt do that either. Does anyone have an idea of what is wrong? Could it be just the footswitch or might there be a problem in the amp itself? Thanks