As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APU START AT FL380, THE FAULT LIGHT ILLUMINATED, AND START ABORTED. TEMP REACHED 950 DEGREES. FOLLOWED QRH. ACFT GROUNDED. REPLACED APU FUEL CONTROL IAW AMM 49-31-11. LEAK CHECK GOOD. PERFORMED BITE CHECK OF APU SYS AND PERFORMED GVI OF AIR INLET DUCT AND COMPRESSOR INLET PLENUM FOR BLOCKAGE. NO DEFECTS NOTED REF FIM TASK 49-30, TASK 803.