As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL400 PAX DOOR OPEN LIGHT CAME ON. REMAINED ON UNTIL DECENDING THROUGH FL370. REMOVED PIN, P/N: 43031-0009 NSN AND INSTALLED CUSTOMER SUPPLIED NEW PIN, P/N: 43031-0009 NSN. PERFORMED OPERATIONAL CHECK OF THE MAIN DOOR OPEN LIGHT WITH NO DEFECTS NOTED. REF EMBS0S 52-10-00.