As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE ADC SWITCHING/ANNUNCIATOR PANEL DEVELOPED A HIGH RESISTANCE SHORT TO GROUND WHICH IN TURN OVERLOADED THE CIRCUIT IN THE AC AND CAUSED THE (A) ESSENTIAL BUS TIE BREAKER TO TRIP. LETTER 2/8/2008 FOR DETAILS. THIS PART WAS INSTALLED AS PART OF STC-STO1199NY-D DUAL ALTIMETER SYSTEM AS PART OF THE RVSM SOLUTION FOR THIS AC.