As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - CREW REPORTED ON GEAR EXTENSION GEAR DOOR OPEN LIGHT REMAINED ON. ACCOMPLISHED GO AROUND AND LIGHT EXTINGUISHED AFTER SEVERAL SECONDS AFTER RECYCLING GEAR. FLIGHT LANDED ORD WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. FOUND TARGET SWITCH RUBBING AGAINST SENSOR. ADJUSTED TARGET. SYSTEM GROUND CHECK NORMAL OPERATION.