As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, LANDING GEAR HANDLE WOULD NOT MOVE INTO UP POSITION. RAN QRH THROUGH P6-3 L/G LEVER/LATCH C/B PULL/RESET. GEAR WOULD NOT RETRACT. RTB DUE TO FUEL CONSIDERATIONS. REMOVED AND REPLACED THE LANDING GEAR ELECTRONIC MODULE IAW 727-200 AMM 32-09-121-4, SWUNG GEAR SEVERAL TIMES WITH NO DISCREPANCIES NOTED. ACFT IS OK FOR CONTINUE SERVICE.