As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING OPS CHECK OF TRANSFORMER RECTIFIER SYSTEM, IT WAS NOTICED THAT THERE WAS NO AIRFLOW FROM THE INTERNAL COOLING FAN. REMOVED AND REPLACED COOLING FAN ASSEMBLY WITH NEW AND IMPROVED UNIT. THERE WAS NO NOTIFICATION TO THE FLIGHT CREW THAT THIS FAN HAD FAILED. (K)