As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#1 ENGINE VIB CAUTION DURING CRUISE FLT @ 350 VIB @ 4.0 FOLLOWED CHECKLIST. VIB RETURNED TO NORMAL RANGE W/ N1 REDUX TO 84 ON #1 ENG. AIRCRAFT DID NOT ENCOUNTER ICING CONDITIONS DURING FLT. REMOVED FROM SERVICE. C/W E175 LMM TASK 72-00-00-810-803 SUBTASK 72-00-00-810-011. NO FAULT NOTED, NO DEFECT NOTED. DEFERRED FAN BLADE RE-LUBRICATION. RETURNED TO SERVICE.