As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, BOTH ENGINE GENERATORS TRIPPED OFF LINE. THE APU WAS RUNNING AND TOOK THE LOAD. THE RT GEN RESET BUT THE LT WOULD NOT. FLIGHT RETURNED TO STL. REPLACED THE BUS TIE UNIT AND RESET THE LH GEN CONTROL UNIT. CHECK-C 4-30-99 STL.