As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS NR 1 ENGINE VIB IN YELLOW IN CRUISE. PERFORMED QRH, WITH AUTO THROTTLE OFF BOTH SIDES INCREASED WHEN THRUST WAS INCREASED. LEFT SIDE LEVEL 2.8 RIGHT SIDE 2.4. MAINTENANCE REMOVED AND REPLACED THE LT AND RT AVM SIGNAL CONDITIONERS IAW AMM 77-31-03. OPS CHECK NORMAL. SEE SDR AALA201905099008.