What was found
HIGH LEFT ENGINE VIB ON TAKEOFF ROLL. REACHED 2.5 IN YELLOW ARC. LEVELED AND RAN QRH HAD POWER BACK TO UNDER 50% N1 TO GET OUT OF YELLOW ARC AND EVEN AT FLIGHT IDLE WE WERE AT 1.6 VIB. ANY USE OF POWER BROUGHT THE VIBRATION LEVEL INTO THE YELLOW ARC. (FLIGHT 3723 - FILED CLOSED) COMPLIED WITH GEMM SP97 AND TASK CARD 12-430-002 FOR REMOVAL AND REPLACEMENT OF LH ENGINE FAN BLADE PINS. VIBE CHECK GOOD