As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#105, JFK-ORD. (AIRCRAFT PERFORMED AN AIR TURN BACK TO JFK) ' DURING CLIMB AND CRUISE #1 ENG LP VIBES REACHED 4.0 AT N1 OF 90.5% VIBES REDUCED WHEN THRUST REDUCED. VIBES FELT IN CABIN; PERFORMED FAN TRIM BALANCE IEVM IAW AMM GE LMM 72-21-00-800-802. PERFORMED POWER RUN, HIGHEST NOTED VIB INDICATION WAS .7 AT 91.6 N1. A/C OK FOR CONT SVC.'