What was found
EICAS MSG R GEN DRIVE DISPLAYED. GEN DRIVE LIGHT ILLUM. GEN DRIVE DISCONNECTED. NOTICED C/B 1 ON FACE OF R GCU WAS OPEN, LIKELY FROM IN FLT. SWAPPED LT & RT ENG GCU'S & RAN RT ENG AGAIN. C/B 1 POPPED AGAIN. BPCU MSGS ARE 28V TO CONTROL SW, GCB-WIRING-GCU, BTB-WIRING-GCU & POWER INTERRUPT. NEED TO FIND WHY C/B 1 IS POPPING. FIM SUGGESTS A PANEL SWITCH PROBLEM, RT GCB (C903), RT BTB (C904). IDG SEEMS TO BE OK. GCU'S STILL IN SWAPPED POS. R & R RT IDG, NO HELP. STILL NOT ABLE TO GENERATE A FIELD. NOTED FIELD OFF LIGHT ILLUMINATED ON P61 PANEL. REPLACED R GEN CONT BREAKER C903 & REPLACED RT BUSS TIE CONT BREAKER C904. OPS CHECKS GOOD, NO FAULTS NOTED.