As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEN DRIVE LIGHT AND GEN DRIVE EICAS MESSAGE ON STEADY BUT WENT OUT WHEN LEFT GEN CONT SWITCH TURNED OFF RESULTING IN AIR TURNBACK AT 50 NM EAST OF DUETS. BITE CHECK BPCU FOUND PRESSURE SWITCH WIRING REMOVED AND REPLACED NR 1 ENG IDG PER HAL CARD 767-3-405001 AND MM 24-11-01, OPS CHECK NORMAL OK FOR SERVICE. (M)