As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF RECEIVED A "NOSE DOOR OPEN" FOLLOWED BY "GEAR DISAGREE" WARNING MESSAGE. RETURNED TO ORD. FLT#6468 PERFORMED CHECK & SWINGS OF THE LANDING GEAR, NOSE GEAR WOULD NOT RETRACT. PSEU FLAGGED SENSOR S23 PS14GA FAR. RERIGGED THE NLG OLEO CENTERED EXTENDED PROXIMITY SENSOR IAW AMM.