if anyone is having a DF-73 being a pain, especially with main boards blowing, check the paper entry transmitting sensor, it is under the top cover, under a black cover, this sensor is secured by a screw with a washer that is too large and overlaps the electrical component on the sensor board, it can make contact with the filament on the sensor board and pop the main board. id replace the screw with one that has no washer, or a smaller washer.