As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ON A DATA GATHERING NIGHT FLIGHT. THE EQUIPMENT POWERED BY THE INVERTER LOST POWER. WHILE REACHING FOR THE POWER DISCONNECT SWITCH, A FLASH WAS NOTICED IN THE AREA IN WHICH THE INVERTER WAS INSTALLED. POWER TO THE INVERTER WAS CUT OFF AND THE AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. (X)