Another change I like to make to these Stern boards is to add a fuse holder for the high voltage for the displays on the output side of the regulator. I know the later Bally/Stern boards have them fitted, and that some later Stern games have a fuse fitted to the back of the hinged lamp/display panel of the backbox, but I wasn’t sure if Wildfyre had one fitted to the panel and added one anyway. And besides it will be useful to have a fuse on the regulator board for another mod I have planned for the future.. a protection circuit for the displays in the event that the regulator section shorts out, feeding 230volts into the displays!! The 2nd pic shows the back of the board, showing where I added the fuse into the circuit (red wires).

Blue wires are for the ground mods and the yellow wire (already fitted by someone else) linking TP1 to TP3 for the 5 volts.

I tested this board in my Stingray game.. all good except for one solenoid driver transistor that needed changing.