As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF RECEIVED A TRIM FAIL AURAL WARNING AND THE TRIM FAIL LIGHT ON THE MAP CAME ON AND CONTINUED FOR APPROXIMATELY 5 MINUTES. RETURNED TO LAX. INSPECTED ELEVATOR TRIM WIRING ON TOP OF TAIL. FOUND CHAFED WIRE TO LEFT PROXIMITY SENSOR AND CORRODED CONNECTOR TO RIGHT SENSOR. REPAIRED WIRE AND REPLACED CONNECTORS. OPS CHECK GOOD.