As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LHR - CREW REPORTED STAB TRIM MESSAGE AND STAB TRIM LIGHT ILLUMINATED. EMERGENCY DECLARED RETURNED LHR LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED LEFT STAB TRIM BRAKED PRESSURE SWITCH. SYSTEM GROUND CHECKED NORMAL OPERATION.