What was found
AIRCRAFT WAS GROUNDED: AFTER TAKEOFF LANDING GEAR DID NOT RETRACT. FLIGHT CREW REPORTED RECEIVED MULTIPLE OTHER WARNINGS. AS WE WERE WORKING THOSE WARNINGS, LANDING GEAR CAME UP. MAINTENANCE REVIEWED THE POST FLIGHT REPORT AND DETERMINED THAT THE MULTIPLE WARNINGS WERE RELATED TO A GEAR WEIGHT ON WHEELS CONFLICT OF THE PROXIMITY SENSORS ON THE MAIN GEARS AND NOTED THAT THE RIGHT MAIN LANDING GEAR PROXIMITY SENSOR 22GA HAD FAULT MESSAGES IN LGCIU #2. MAINTENANCE REPLACED PROXIMITY SENSOR 22GA ON THE RIGHT MAIN LANDING GEAR PER AMM 32-31-73-400-001.