As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR RETURN - PILOTS REPORTED THAT THE GEAR WOULD NOT RETRACT AFTER TAKEOFF. HANDLE DID MOVE UP. A TURBULENCE NOISE WAS OBSERVED AS IF THE DOORS WERE OPEN. 6 GREEN AND 6 RED LIGHTS ILLUMINATED. CYCLED GEAR GEAR 4 TIMES. WITH GEAR HANDLE DOWN 6 GREEN LIGHTS OBSERVED AND THEN THEY RETURNED TO THE DEPARTURE AIRPORT. MAINTENANCE REMOVED AND REPLACED THE NR 1 GEAR DOOR SEQUENCE VALVE IAW 32-32-04 AND ADJUSTED THE ACTUATING BOLT ON THE DOOR BELL CRANK. OPERATIONAL TEST WAS GOOD IAW 32-32-00.