As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 4230 - DURING CLIMB, CREW WAS NOT ABLE TO BRING NOSE DOWN WITH CAPTAIN, F/O OR STANDBY PITCH TRIM BEFORE GETTING PITCH TRIM FAIL ON EICAS. CREW DECLARED EMERGENCY AND RETURNED TO ORD AND LANDED SUCCESSFULLY. MAINTENANCE REMOVED AND REPLACED HORIZONTAL STABILIZER CONTROL UNIT IAW EMB MM. OPS CHECK WAS GOOD. (M)