Sounds like a circuit overload. Try plugging the amp into a different receptacle on a different breaker. There should be no way for the amp to sense the status of the 976 without the trigger connected. Amps can have large inrush currents when first started. If the current is still there when the 976 comes on the amp may go into protection mode. Check all your connections to make sure no stray wires are crossing. As a extra check look at your trigger settings in the menu.