What was found
LEFT ENGINE N3 VIB WENT TO 5.0 /AMBER/ TWICE FL380 .78 REDUCED T HRUST N3 STABLE AT .8 AS PART OF OTHER TROUBLESHOOTING, REPLACEMENT OF THE #1 ENG AVM HAS BEEN CARRIED OUT, REF AMM 77-31-04-404-017, OPERATIONAL CHECK OK.ACCELEROMETER REPLACED, AND OPERATIONAL CHECK AT IDLE GROUND RUN CARRIED OUT, NO FAULTS WITH VIBRATION SYSTEM, NO FAULTS SHOWN ON AVM SIGNAL PROCESSER, REF AMM 73-31-04-404-017-R00. TROUBLESHOOTING CARRIED OUT WITH REF TO FIM 77-31 FAULT TREE 807, & TOMC/ENGINE DESK REQUESTS. NO VIBRATION FAULTS FOUND, ENGINE IDLE RUNS COMPLETE. CREW BRIEFED AND OK FOR FERRY FLIGHT.