As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING LINE CHECK, THE PILOT FOUND HE COULD NOT CONTROL THE EMERGENCY LIGHTS IN THE CABIN AT THE L1 DOOR, IT WOULD REACT WHEN CONTROLLING CABIN LIGHTING. MAINTENANCE REPLACED THE POWER SUPPLY FOR THE NOTED LIGHTED AREAS AND THE OPERATIONAL CHECK WAS GOOD.