What was found
FAN VIBRATION 4.1 AT CLB THRST TO FL270. AT CRUISE VIB IS 1.0. NO AIR FRM VIB FELT. OIL TEMP AND PRESS PER CREW DEBRIEF: ALL OTHER ENGINE INDICATIONS WERE NORMAL DUE TO PILOT REPORT OF VIBRATION NOT FELT IN FLIGHT DECK, PERFORMED FIM 77-31 FAULT TREE 808. SWITCHED TO ALTERNATE/EXTERNAL NO.1 ACCELEROMETER. PERFORMED VIBRATION SURVEY PER AMM TASK 71-00-00-735-320-H03. VIBRATION PEAKED AT 2.1, STATUS MESSAGE ENG L VIB APPEARED. ALSO FOUND LPT PH VIBRATION INDICATION INTERMITTENT FOR NR 1 ENGINE DURING SURVEY. PERFORMED TRIM BALANCE IAW 72-31-00-705-119-H00 MAX VIB AFTER BALANCE WAS 0.2 AT 103% N1. OK TO CONTUNUE.