As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON DEPARTURE FROM DTW, THE CREW FOUND THAT THE GEAR INTRANSIT LIGHT WOULD NOT EXTINGUISH. THE CREW FOLLOWED THE QRH AND RETURNED TO DTW WITHOUT INCIDENT. INSPECTED UPLOCK SWITCHES AND FOUND NLG SWITCH COVERED WITH SAND AND ICE. CLEANED SWITCHES. DID EXTENSION AND RETRACTION IAW 32-30. ALL CHECKS GOOD.