I got a used 4B-ST-Pro for my ProTools rig, to drive my Dynaudio BM15s, and in the last few months I've been having trouble with one of my channels dropping out. I've been switching cables, bypassing components (thought one of the channels in my Digi001 was out), and general troubleshooting. But, today when messing around I discovered that if I switch the 'Bridged/Individual' switch to 'Bridged' I get both channels, when it's on 'individual' I only get the right channel. Also when moving the switch I get a lot of static. Any ideas? I may have been accidently moving the switch earlier, I've forgot to switch the 'Balanced/Unbalanced' switch before, so that was why I was messing with the back of the unit.