As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSTRUMENT NUT CAME OFF VSI AND SHORTED FROM AM/FM RADIO CASE TO TOP TERMINAL OF CIRCUIT BREAKER FOR THE TURN BANK INDICATOR, CAUSING WIRE FROM BUS TO CIRCUIT BREAKER TO BURN. CHECK ALL INSTRUMENTS FOR MISSING SCREW AND REMOVE AM/FM RADIO FROM AIRCRAFT.