What was found
INSPECTION TYPE:NA**ATB** VIBRATION UNDER BOTH PILOTS FEET, ACCOMPANIED BY A HUMMING SOUND EVERY TIME CONTROL WHEEL TRIM SWITCHES WERE ACTIVATED IN FLIGHT IN EITHER DIRECTION. ISSUE WAS NOT PRESENT DURING AUTOPILOT TRIM OPERATIONS. COULD FEEL VIBRATION IN BOTH CONTR. PERFORMED VISUAL AND AUDIO INSPECTION OF VERTICAL STAB COMPONENTS IN JACKSCREW COMPARTMENT WHILE EXCERCISING VERT STAB SWITCHES NORMAL & ALTERNATE. NO VIBRATION OR UNUSUAL NOISES FOUND. RT (NEXT WORD ILLEGIBLE-LOOKS LIKE "SAM") SHOWED STCM FAULT BALL. R&R'D RT STCM PER MM 27-41-05-024 & 27-41-05-424.