As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT LOST ALL AVIONICS POWER WHILE IN LEVEL FLIGHT, PILOT DECLARED EMERGENCY LANDING AND LANDED AIRCRAFT WITHOUT INCIDENT. MECHANICS DETERMINED THAT THE STARTER RELAY SHORTED INTERNALLY CAUSING A SHORT THAT TOOK OUT THE AVIONICS BUSS CAUSING THE POWER LOSS. RELAY WAS REPLACED AND AIRCRAFT RETURNED TO AIRWORTHY CONDITION.