As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF LEFT MAIN GEAR RED LIGHTS WON'T EXTINGUISH. COULD FEEL GEAR NOT RETRACTING. FOLLOWED QRH PROCEDURES AND RECYCLED WITH SAME RESULTS. ADJUSTED LEFT MAIN LANDING GEAR PROXIMITY SENSOR. CYCLED GEAR SEVERAL TIMES. SYSTEM OPS CHECK GOOD.