As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING OPERATION CHECK OF THE EMERGENCY LIGHTING SYSTEM, FOUND CEILING PANEL 253BLC AFT EMERGENCY EXIT LOCATOR SIGN INOP. AIRCRAFT WAS REMOVED FROM SERVICE FOR IMBV INSPECTION AND WILL BE RETURNED TO SERVICE AFTER IMBV INSPECTION. REMOVED AND REPLACED CEILING PANEL 253BLC AFT EMERGENCY EXIT LOCATOR SIGN DC TO AC INVERTER 4 IAW AMM 33-50-11. OPERATIONAL CHECK GOOD. AIRCRAFT WILL BE RETURNED TO SERVICE AFTER IMBV INSPECTION.