As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TOTAL FUEL WENT FROM 39.4 TO 38.7 IN 20 MIN ON APU ONLY. ACFT GROUNDED. REF FIM 28-41, TASK 807 FOUND FAULT FOR NR 1 TANK 28-41108 & NR 2 TANK 28-41208. REPLACED NR 1 F/Q COMPENSATOR PROBE REF AMM 28-41-21-000-801/400-801. OP CHECK NORMAL REF MM 28-41-00.