I just bought my first pinball machine but it's got some issues. After the score test the machine will lock up. I can turn it back in ten minutes later and it will play. I can get one game in and get one more game out of it and it locks up again. The scores will get to 8 on all of the scores. I replaced the mpu board and still the same thing. I can shut it off and wait ten minutes and I can play it again. Any suggestions?