As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOTH STAB AND MACH TRIM CAUTION LIGHTS CAME ON DURING FINAL APPROACH. UNABLE TO RESET TRIM FOR MORE THAN 10 TO 15 SEC BETWEEN DISCONNECTS. REPLACED HORIZONTAL TRIM ACTUATOR AND HORIZONTAL TRIM MOTOR CONTROL UNIT AND THE HSTCU, OPS CHECKS GOOD IAW 27-41-00-740-801. MOTOR CONTROL UNIT P/N: 9062-3, S/N ON: 961, S/N OFF: 757. HSTCU P/N: 7060-9, S/N OFF: 1364.