As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GNDED. ON FINAL DESCENT, A STRONG SMOKE & BURNING PLASTIC SMELL IN THE COCKPIT WAS REPORTED BY THE FLIGHT CREW. FOUND THAT THE AVIONICS BLOWER FAN 20HQ HAD AN ELEC SMELL & WAS VERY NOISY RESULTING IN THE REPLACEMENT OF THE FAN IAW AMM 21-26-51-000-001-A.