As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSPECTION TYPE:ETOP DURING PS-CHECK, STARTING APU MECHANIC NOTICED SMOKE IN COCKPIT. FURTHER INVESTIGATION FOUND STATIC INVERTER IN E3 RACK CAUGHT FIRE. REMOVED STATIC INVERTER AND FIRE HAD BEEN EXTINGUISHED BY FIRE FIGHTER, NO DAMAGED ADJACENT COMPONENT.