As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ELECTRIC MESSAGE LIGHT ILLUMINATED UPON APU START UP ON OVERHEAD PANEL. ACFT GROUNDED. REPLACED STANDBY POWER CONTROL UNIT. REPLACED STATIC INVERTER, PN 1-002-0102-2090, SN CJ006190 ON E2-2 EQUIPMENT RACK. FIXED DAMAGED CONNECTORS, TERMINALS, WIRES. OPS CHECK OF SPCU AND STATIC INVERTER GOOD REF AMM24-34-11 AND AMM24-34-21. RAN APU WITH NO FAULTS ON BITE TEST OF ELECTRIC PANEL.