As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT, EMER LIGHTING CHECKED WITH BATTERY HOOKED UP AND BATTERY SWITCH IN THE OFF POSITION. MAIN CABIN DOOR EXIT SIGNS ABOVE DOOR AND ON EACH SIDE OF THE MAIN CABIN DOOR WOULD NOT ILLUMINATE. ALL MAIN CABIN DOOR LIGHTING WILL ILLUMINATE, WHEN THE BATTERY SWITCH IS IN THE ON POSITION. SIGN-OFF. REMOVED AND REPLACED FWD EMERGENCY BATTERY PACK, REF CESSNA 560XL MM 33-50-01. OPS CHECK GOOD.