What was found
PRECAUTIONARY SHUTDOWN OF LEFT ENGINE DUE TO N3 VIBRATION IN AMBER BAND 4.3 YELLOW. BROUGHT ENGINE TO IDLE STILL IN AMBER BAND 4.3-3.9, CHECKED LT ENG MASTER CHIP DETECTOR. CONDITION NORMAL. MEASURED WIRING N3 TACHOMETER TRANSMITTER TO LT AVM & VIBRATION TRANSDUCER TO LT AVM, CONDITION SATISFACTORY. IAW AMM 77-31-03, R & R AVM & AMM 77-31-00 TEST AVM SYS NORMAL IAW AMM 71-00-00 PFM LT ENG RUNNING CHECKED VIBRATION, CONDITION SATISFACTORY. P