What was found
DURING ATTEMPTED NR ENGINE RUN FOR HIGH VIBRATIONS, FOUND THE ENGINE VIBRATION INDICATIONS GO BLANK AFTER REACHING 109% N2, DURING START. ACFT GROUNDED. GVI THE BACK OF THE E3-2 SHELF, NO FAULTS FOUND, GVI THE NR 1 ENG VIBRATION SENSORS AND WIRING . NO DEFECTS NOTED , REMOVED & REPLACED THE ENGINE VIBRATION MONITOR IAW AMM 77-31-03-400-801-F00. REMOVED AND REPLACED AND ALL THE FAN BLADES IAW AMM 72-21-02-000-801. ACCOMPLISHED VIBRATION SURVEY IAW T/C 78472002. VIBRATION LEVELS WELL WITHIN LIMITS.