What was found
DURING AN ANNUAL INSPECTION OF THE ELT UNIT, THE ELT BATTERY PACK WAS INSPECTED FOR CORROSION IAW FAR 91.207 PARA (D). VOLTAGE WAS PRESENT AT THE POWER SUPPLY PLUG PRIOR TO DISCONNECTING. THE BATTERY POWER SUPPLY ELECTRICAL PLUG WAS DISCONNECTED AND INSPECTED OK, NO CORROSION. THE BATTERY POSITIVE TERMINAL WAS CHECKED WITH A VOLTMETER, VOLTAGE WAS NOT PRESENT AT THE CONNECTION PLUG POWER TERMINAL END. THE BATTERY PACK POWER AND GROUND ARE ROUTED THROUGH A CIRCUIT BOARD GLUED INSIDE OF THE HOUSING. ONE OF TWO FUSES SOLDERED ON THE BOARD TESTED (OPEN), CAUSE UNKNOWN.