As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) WHILE AIRCRAFT WAITING ON THE GATE TO BOARD PASSENGERS FOR DEPARTURE, SMOKE WAS OBSERVED IN THE COCKPIT. CAUSE OF SMOKE WAS DETERMINED TO BE THE NR 2 TRANSFORMER RECTIFIER. UNIT REPLACED WITH NO FURTHER DEFECTS. (TC# 20060706004)