I had gotten an inquiry about 49-way joysticks for NFL Blitz 1999 or 2000 (because they specified the presence of an I-40 board) where the joysticks are non-responsive and all inputs will be lit up in Switch Test.
I had encountered this problem years ago when I had all my games moved and had to remove the control panel to get the game through the door. Mine was a Blitz 1997 that had been upgraded to Blitz 1999 later, I don’t know why Blitz 1997 would have needed fuse because those joysticks interfaced directly into the Seattle board instead of an I-40 (your mileage may vary if you’re running a Vegas Sportstation), but I had 2 sets of fuse wires. It required a lot of trial and error for me to figure out, but I have some instructional guidance that may help make this process a lot easier for anyone else to figure out!
I procured a visual aid of how everything hooks up.
The fuse takes +5V in, so with your multimeter start continuity/beep testing from the +5V at the power supply to all the available fuse wires you may have. The one that’s connected to the power supply will be the source voltage. The other wire you’ll need to find then for the fuse holder is the one that runs to the I-40 board. It may be easiest to have the power plug connected (whichever has a solid red wire) and to unscrew the board out and flip it over to continuity/beep test against the header pin where the red wire runs. That will be the target voltage end taking the +5V from the power supply to the fuse holder, through the fuse, and to the I-40. I’m assuming the I-40 board sources its ground from the input wiring running back to the Seattle/Vegas Aux. Adapter Board to complete the power circuit.
With the power to the I-40 addressed, you should have functioning 49 way joysticks. If you’re missing directional inputs at any of the joysticks you will have a separate logic issue at the 49 way joystick optical boards. I don’t remember how many chips are on these, but they’re 74LS00 chips. Seattle schematics exist, but I’ve never looked at them and am unsure if the joystick schematics are contained within. These are Happ parts, so maybe with some digging… otherwise if you have visual aids of the board to send to me let me know.
As a bonus, there is a way to adapt an original Seattle cabinet to connect the Volume Up/Down harness to a Vegas Sportstation board.
The clunky method to getting the whole test panel to work in a conversion to Sportstation.
All components in a Vegas system.
The Vegas control interface, Aux. Adapter Board, or as seen here, “Adatper”. 🙂