Quoted from XPinPinball:

I want to weigh in on this one. I have been in communication with PUSH600 and I am just as much a loss with this one as everybody. This design has been in production for years and typically at about 75% max brightness each display draws about 35mA. This would be a first for the 5v regulator to fail on the driver board.
When first developed there were problems with the 5v system, particularly if the driver board was an early rev with the 2A regulator on the board, and resets would occur.
I will continue working with PUSH600 on this problem. I would like to see this resolved as well.
Brett