What was found
DURING CRUISE AT FL 330, A STRONG ELECTRICAL ODOR DETECTED IN THE COCKPIT AND A NOTICEABLE VIBRATION, HUMMING NOISE FELT AND HEARD. INDICATED SMOKE, AVIONICS SMOKE FUMES QRH PROCEDURE AFTER SELECTING BLOWER TO OVERRIDE THE ODOR DISSIPATED AND NOISE, VIBRATION DECREASED. REPLACED AVIONICS BLOWER FAN IAW AMM 21-26-51. ACCOMPLISHED OPERATIONAL TEST OF THE VENTILATION SYSTEM OF THE AVIONICS EQUIPMENT IAW AMM 21-26-00-710-001.