What was found
(CAN) ENROUTE, EXPERIENCED AN ACRID ELECTRICAL ODOR ON THE AIRCRAFT. UNABLE TO ISOLATE THE ORIGIN SO THE CREW ELECTED TO DIVERT. A EMERGENCY WAS DECLARED. INSPECTED ALL PANELS FOR SIGNS OF OVERHEAT OR BURNED COMPONENTS. WIRES INSPECTED FOR ARCHING OR BURNED AREAS, NO FAULTS FOUND. FOUND CIRCUIT BREAKER TRIPPED ON APPLICATION OF GROUND SERVICE. REPLACED 2420VD DIODE MODULE AND RELAY 6XX, RESET CIRCUIT BREAKER FOR EXTERNAL POWER. GROUND POWER NOW WORKING NORMAL. RAN ENGINES FOR 1 HR NO BURNING ODOR IN FLIGHT DECK. AIRCRAFT ENERGIZED FOR 7 HRS WITH NO FAULTS. SYSTEM SERVICEABLE.