As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAX - FLIGHT NR 2330: LANDING GEAR FAILED TO RETRACT AFTER TAKEOFF. MAINTENANCE INTERROGATED THE PSEU AND FOUND CURRENT FAULT OF 'NWCENT FAULT', 'PROX SENSOR OPEN', ALSO FOUND ON FAULT HISTORY 'NWCENT FAULT', 'PROX SENS OPEN'. REPLACED NOSE GEAR WOW NR 2/CENTERING ELECTRICAL HARNESS AND OPS CHECK IAW AMM 32-21-11-000-801/32-21-11-400-801. NO CURRENT FAULTS NOTED. GROUND CHECKS NORMAL. AIRCRAFT RETURNED TO SERVICE.