As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT, FOUND ELECTRIC LIGHT ON. ACFT GROUNDED. BITE TEST SHOWS "SPCU INOP" FAULT. CHECKED SPCU FOR INSTALLATION SECURITY & CHECKED RELATED CIRCUIT BREAKERS, NO DEFECTS NOTED. REPLACED P5-13 ELECTRICAL METERS MODULE REF MM 24-21-53. OPS NORMAL.