Hi, I am working on a Williams Firepower. When I got the machine the #2 display was burnt out. The master display board was also missing the match lights so I bought a used kit with four displays and a MDB. I installed the MDB and replaced the #2 display. Over the next few days as I was playing it, all worked well. Then suddenly I see a puff of smoke and saw the #2 display arcing at the bottom of the glass. I turned the game off. I thought it was odd that another #2 display location burnt out. I pinned out each wire from the MDB to each display to make sure someone hadn't done some mis-wiring in the past. All four displays were wired as they should be based on the schematic. Voltage to the MDB and to each display is +100v. It could be a coincidence that the used display burnt out but not sure. Anyone have any thoughts on what else I could check?