As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN CARGO DOOR LIGHT CAME ON SHORTLY AFTER TAKEOFF. AIRCRAFT RELEASED FOR SERVICE PER MEL/CDL: 52-4A, MCD VERIFIED CLOSED. REMOVED AND REPLACED CONTROL SWITCH ARM/DISARM SWITCH. REMOVED AND REPLACED DOOR UNLOCK LT ON MANUAL HAND PUMP PANEL. C/B CARGO DOOR WARNING DOESN'T POP.