As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
R GEN DRIVE MESSAGE ILLUMINATED. PERFORMED BITE ON BPCU. FAULTED RT GCU. REPLACE RT GCU. PERFORMED BITE. NO FAULTS. RESET GENERATOR DISCONNECT. RAN ENG ON IDLE AT GATE. NO VOLTS OR FREQS. REMOVED AND PLACED R IDG IAW M/M. RAN ENG AT GATE. DISCONNECTED IDG. RESET DRING AND RE-RAN ENGINE. OPS CHECK NML MPN 755359.