As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VIBRATION IN YOKE ON GROUND. WORST ON F-O SIDE. FOUND NO VIBRATION WITH APU OFF. VISUAL INSPECTION OF APU MOUNTS, STRUTS AND BRACKETS - NO OBVIOUS DEFECTS NOTED. DUCTS AND APU EXHAUST SECURE. RAN APU, NOTED NO LOOSE OR VIBRATING ITEMS. FOUND FOREIGN IMPACT DAMAGE 1 STAGE BLADE. APU REPLACED.