As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT SHUTDOWN ; AFTER. COMPLETION OFF PARKING CHECKLIST & WHEN SELECTING JETWAY POWER A/C WENT COMPLETELY BLACK EMER LTS WERE ARMED & DID NOT ILLUMINATE AND WERE NO CABIN LIGHTS <[01]. FOUND CIRCUIT BREAKER ?28VAC GND SERV 1? TRIPPED ON THE P91 PANEL. SUSPECT BAD GATE POWER. RESET CIRCUIT BREAKER PER AMM 20-60-01. CABIN LIGHTS AND GROUND SERVICE RETURNED TO NORMAL. REF AMM 33-20-00. NO FURTHER DEFECTS NOTED. OPS CHECK GOOD.