As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PITCH TRIM MAIN INOPERATIVE, EICAS MSG APPEARED ON THE GND WHEN POWERING UP ACFT & THE MSG DIDN'T RESET. TROUBLE SHOT & FOUND HORIZONTAL STABILIZER CONTROL UNIT FAILED. INSTALLED TESTED UNIT. OPERATIONS CHECKED GOOD, RETURNED THE ACFT TO SERVICE.