As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT 3621, GEAR UNSAFE LIGHT DURING GEAR RETRACTION FROM MISSED APPROACH. RECYCLED THREE TIMES. AIR RETURN TO DTW. JACKED AC FOR GEAR SWINGS, NOTED EXCESSIVE MOISTURE RT, LT DOOR AND GEAR UPLOCKS. CLEANED AND LUBED LOCKS IAW AVRO AMM CH 12. SUSPECT ICE BUILD-UP. PERFORMED MULTIPLE GEAR SWINGS. ALL CHECKS GOOD IAW CH 32.