What was found
ENGINE 1 N1 VIBRATION. AT CRUISE, MOVED THROTTLES FROM CLIMB TO CRUISE RANGE. N1 VIBRATION INCREASED TO 2.1 WITH NOTICEABLE VIBRATION CHANGE AND SOUND. CONTINUED TO DECREASE POWER UNTIL VIBRATION IN NORMAL RANGE. ENGINE VIBRATION WOULD THEN INCREASE AGAIN INTO CAUTION RANGE. FOLLOWED QRH AND ELECTED TO SHUTDOWN ENGINE BECAUSE VIBRATION COULD NOT BE CONTROLLED. REPOSITION FLIGHT NO PAX. (FLT#4980) CLOSED REMOVED AND REPLACED NR 1 ENG ALL 28 FAN BLADE PINS IAW MM. VIB CHECK GOOD AT THIS TIME.