As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI NR 2 COM NAV DISPLAY WENT BLANK, APPROXIMATELY 5 MIN LATER DISPLAY WENT FULL BRIGHT THEN BEGAN TO SMOKE AND WENT BLANK AGAIN. AIRCRAFT RETURNED TO BLOCK. REPLACED RADIO MANAGEMENT UNIT IAW CE-650 MM CHAPTER 23-11-10, SYSTEM OPS CHECKED GOOD.