As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HEARD ODD PULSATING SOUND AND BEGAN SMELLING ACRID ELECTRICAL SMOKE SMELL. RAN SMOKE /FUME/AVIONICS SMOKE CHECKLIST AND SMELL AND SOUND DISSAPATED WHEN VENTILATION FANS WERE TURNED OFF. REMOVED AND REPLACED AVIONIC FAN IAW AMM 21-26-51-000-001-A / 400-001-A OPS CHECK OK.