As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BEHIND LEFT PILOT SEAT, A LOUD SQUEALING NOISE STARTED FOR ABOUT 10+ MINS THEN FOLLOWED BY A STRONG BURNING ODOR IN THE MAIN CABIN. THEN IT QUIT. TROUBLESHOT AND FOUND AVIONICS COOLING FAN TO BE THE SOURCE OF THE SQUEALING AND BURNING ODOR. REMOVED AND REPLACED THE COOLING FAN. ALL WORK PERFORMED IAW AMM 21-23-05. OPS CHECKED GOOD.