As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY LIGHTING SYSTEM OPERATIONAL CHECK {B737-33-3-0235} - FIRST CLASS FLOOR PATH LIGHTING DOES COME ON BUT GOES OUT AFTER APPROXIMATELY 20 SECONDS. THE AIRFRAFT HAS BEEN RUNNING FOR 5 HOURS ON APU POWER. NO IMPROVEMENT IN TEST DURATION. REMOVED & REPLACED FIRST CLASS EMERGENCY LIGHT BATTERY REF 33-51-06. OPERATIONAL CHECK GOOD.PARTS USED: AD-D717-01-100, QTY :1