As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EICAS MSG R GEN OFF DISPLAYED. GEN OFF LGT ILLUM AND FAILED TO RESET. REPLACED GCU AND REPLACED IDG, NO HELP. ALSO SWAPPED BUSS POWER CONTROL UNIT, NO HELP. REINSTALLED OLD BPCU. WIRE HARNESS REPAIRED. ACP 'D GROUND ENGINE RUN. GEN OPS CHECK OK.