As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ELEC LIGHT ILLUMINATED UPON MASTER CAUTION RECALL, AFTER ENGINE START AND TRANSFER BUSSES COVERED BY RESPECTIVE ENGINE GEN. GROUNDED-YES. PERFORMED ELEC LIGHT BITE TEST, PER B737-800 FIM 24-31 TASK 801, FAULT CLEARED. FOUND FAULTS APU BATTERY AUX CHARGER, STAT INV, & SPCU MESSAGE. ACCOMPLISHED FAULT RESET ALL FAULTS CLEARED NO OTHER ACTIONS NOTED. A/C OK FOR SERVICE.