As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PRIOR TO PUSHBACK HEARD A STRANGE SOUND FOLLOWED BY A BURNING SMELL. MAINTENANCE ACCOMPLISHED JOB CARD 05-96-70. SMOKE/ ODOR TROUBLESHOOTING. FOUND THE AVIONIC VENT BLOWER FAN SEIZED UP WITH AN ELECTRICAL SMELL COMMING FROM IT. REMOVED AND REPLACED BLOWER IAW AMM 21-26-51. A/C OK FOR SERVICE.