As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT UPON AIRCRAFT POWERUP, THE NO2 PIC MFD SCREEN STARTED SMOKING. THE CREW QUICKLY POWERED DOWN AND THE SMOKE DISSIPATED. THE MAINTENANCE PROVIDER INSPECTED THE DISPLAY UNIT NO2 FOR DAMAGE AND FOUND THE NO2 DISPLAY UNIT CONTROLLER HAD BURNT CIRCUIT BOARD. THE NO2 DISPLAY UNIT WAS REMOVED AND REPLACED WITH A REPAIRED UNIT. OPS CHECKS WERE SATISFACTORY, AND THE AIRCRAFT WAS RETURNED TO SERVICE.