As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ROTATION ON TAKE-OFF, THE FLIGHT CREW RECEIVED A MAIN PATCH TRIM INOPERATIVE MESSAGE ON EICAS. THE BACK TRIM SYS FUNCTIONED NORMALLY AND TERE WAS NO RUN-AWAY TRIM SITUATION. THE QRH WAS FOLLOWED BUT THE MAIN TRIM WOULD NOT OPERATE. THE AIRCRAFT LANDED BACK AT EWR WITHOUT INCIDENT. MAINT RESET THE TRIM SYSTEM AND THE MAIN TRIM SYS FUNCTIONED NORMALLY. (K)