My shaker motor wasn't working in mine. They position that board so close to the motor that the vibrations hit it pretty hard and cause components to vibrate off or solder joints to loosen. The board itself is very simple. The big 1W resistor on mine had come loose and all I had to do was solder it back down. I reflowed all solder on the board just to be sure.

As far as backbox GI, DE games are notorious for burnt connectors on the GI. Check for a burnt connector on the power board, replace it, and put LEDs or 47s in and you should be good to go.