As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ENGINE START, UNUSUAL AIRFRAME VIBRATION. AIRCRAFT RETURNED TO BLOCKS. (BTB). PERFORMED FLT CONTROL CHECK IAW AMM 27-00-00, NO DEFECTS FOUND. ADDED MORE FUEL TO AIRCRAFT AND PERFORMED ENGINE IDLE RUN IAW AMM 71-00-00 OPS GOOD, NO VIBRATION NOTED. AFTER MORE WEIGHT ON AIRCRAFT. AIRCRAFT RETURNED TO SERVICE.