As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEG - FLIGHT 2353 - AFTER DEPARTURE, THE LANDING GEAR WOULD NOT RETRACT WITH THE HANDLE IN THE UP POSITION. MAINTENANCE INSPECTED THE AIRCRAFT AND REPLACED THE #2 WOW PROXIMITY HARNESS. THE HARNESS/SYSTEM WAS RIGGED, OPERATIONAL CHECKS WERE PERFORMED AND THE AIRCRAFT WAS RETURNED TO SERVICE.