As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE COMING OUT OF SEAT ELECTRONIC UNIT. DISCONNECTED WIRES TO UNIT AND POWER SWITCHED OFF TO ENTERTAINMENT SYS AND LAPTOP POWER. THE VIDEO DISTRIBUTION BOX AT SEAT 13F FAILED. THE UNIT WAS REPLACED AND ENTERTAINMENT SYSTEM OP CHECKED OKAY. THE UNIT WAS EXAMINED IN COMPONENT SHOP AND FOUND CHIP FAILURE ON THE MAIN CIRCUIT BOARD.