As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VIBRATION IN FLOOR AREA OF ROWS 56-58 ON RT SIDE, UNABLE TO ISOLATE WITH RECIRCULATING FANS OR GASPER FAN. SUSPECT POSSIBLE LAVATORY GALLEY VENTILATION FAN. DEFERRED SECONDARY LAVATORY GALLEY VENT FAN. PULLED & COLLARED CIRCUIT BREAKER ON P84 AS PRECAUTION. VIBRATION NOW STOPPED. REPLACED SECONDARY LAVATORY GALLEY VENT FAN IAW AMM.