As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKEOFF, THE NOSE GEAR DID NOT RETRACT. THE MAIN RETRACTED NORMALLY, HAD A NOSE GREEN AND A RED UNLOCK LIGHT. HEARD SURGING AND MOVEMENT OF THE NOSE GEAR EVERY 10 SECONDS OR SO AS THE NOSE GEAR TRIED TO RETRACT. WHEN LANDING GEAR HANDLE WAS LOWERED, HAD 3 GREEN AND NO RED AND A NORMAL LANDING. POSTFLIGHT INSPECTION SHOWS NO OBVIOUS REASONS FOR NOT WORKING PROPERLY. REMOVED AND INSTALLED OVERHAUL NOSE WHEEL STEERING UNIT. OPS CHECKED GOOD.