As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OVER FFU VOR THE INSTRUMENT INDIRECT LIGHTS STARTED FLICKERING INTENSELY. SHORTLY AFTER THERE WAS A STRONG BUT DISTINCT SMELL OF BURNING ELECTRONICS. THEN THE POTENTIOMETER FOR THE INSTRUMENT INDIRECT LIGHTS BECAME AN “ON/OFF” SWITCH, AND THE SMELL BEGAN TO FADE.