As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURN BACK, BOTH ENG GENERATORS DROPPED OFF LINE, SHORTLY AFTER RAISING LG. ENG GENERATORS WOULD NOT COME BACK ON LINE. STARTED APU & AFTER NUMEROUS ATTEMPTS WAS ABLE TO GET APU GEN ON LINE. HAD POWER ON ACFT BUT ALL WARNING LIGHTS INDICATED NO POWER ON ACFT. APPROX. 1/2 OF ALL WARNING LIGHTS ON ACFT WERE ILLUMINATED. NO POWER TO CABIN. R & R ACFT SYS GENERATOR APU MODULE IAW MM.