As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW NOTICED SMOKE COMING FROM BEHIND INSTRUMENT PANEL WHILE PREFORMING PREFLIGHT WITH ELEC & AVIONIC POWERED ON. CREW TURNED OFF BATTERIES & DISCOUNTED APU. DETERMINED RT FLIGHT DISPLAY WAS SMOKING. INSTALLED OVERHAULED UNIT. ACFT WAS RETURNED TO SERVICE.