As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE MASTER SWITCH IS DIVIDED INTO TWO SWITCHES A THAT ARE COUPLED TOGETHER WITH A PLASTIC TAB. THE HALF OF THE SWITCH THAT CONTROLS THE ALTERNATOR FIELDS IS HIDDEN UNDER THE SIDE PANEL. WHEN THE TAB THAT COUPLES THE TWO TOGETHER BROKE, THE ALTERNATORS DROPPED OFF LINE.