Quoted from shicketmaster:Troubleshooting a Hook machine.
1) I initially installed a Rottendog MPU along with all of my other changes(Rottendog playfield power, Rottendog Flipper board, New Pinsound Board) and the Pinsound board worked initially. Then after turning the machine off, it would only work randomly. It appears that the Rottendog MPU and the Pinsound board don't always communicate. I contacted PinSound and they are working on a firmware update to make the board more responsive to recognizing the Rottendog MPU each time since I wasn't the only person with this problem.
I have a Rottendog MPU and Pinsound board and have the same problem on my DE Star Wars.
Sometimes I have to turn it on 3 or 4 times before the sound works.