When troubleshooting an arcade game, you might get to a point where you start to suspect that your board has issues. Swapping in a tested, working board in JAMMA wired cabinets is an easy way to find out if it’s your current board or the cabinet that’s causing your issues. In this post, we will discuss how to swap boards in a JAMMA cabinet for testing and conversion purposes.
Swapping Boards In A JAMMA Cabinet
As mentioned in the introduction, we highly recommend keeping extra JAMMA boards around for testing purposes. Some good candidates for test boards include 8 liners boards (such as cherry master) or older JAMMA games from the late 80s and early 90s. You can purchase these types of boards pretty cheap at arcade auctions or even off of eBay. It’s OK if the board that you use for testing is not 100% working. We use an old Street Fighter 2 board that has some graphical glitches but it works well enough to tell if our cabinet is working properly.
Before we begin the process of swapping out our JAMMA boards, we recommend checking the power supply to make sure it’s working properly. Keep in mind that the board expects a certain voltage to be connected to specific pins on the JAMMA harness. Board damage or malfunction can result from incorrect voltages being sent to these pins from the power supply. Please review our post on Checking And Replacing A Power Supply for more information on checking the voltages coming from your power supply.
Once we’ve checked our power supply, we can begin the process of swapping out our JAMMA boards. Begin by opening up your cabinet and locating the board that is currently connected to the harness. Slowly remove the JAMMA harness from the board. Make sure you note the location of pin 7 (known as the key) on your main harness as you remove the board. The key helps you identify how to plug the new board into your harness. Many JAMMA harnesses have a plastic placeholder in this spot which prevents you from plugging the board into your harness incorrectly. Keep in mind that plugging the board in backwards might cause damage to your board. You might notice an additional harness (known as a kick harness) inside of your cabinet. If your cabinet has a kick harness, remove it from the board after the main JAMMA harness. At this point, you can either remove the board from the cabinet or find a partition (such as a piece of cardboard) that will prevent the current board from touching the new board.
With the harness removed from the current board, we can proceed with connecting our new board. Locate the harness coming from the cabinet. Make sure that the key on your harness matches up with the key on your new JAMMA board. Place the harness on the JAMMA connector in the correct position. You should now be able to turn your cabinet on and get a picture on the monitor. Please note that you might have some problems with your control panel especially if your new board requires a kick harness. Unless the original board and the new board use the same system, you will probably need to hook up a different kick harness to your cabinet to get all of your controls working. If you are only using the new board as a test board, plugging up the main JAMMA harness should be enough to tell if your power supply and cabinet wiring are working.
Whether you’re trying to track down problems with a game or installing an entirely new board, swapping boards in a JAMMA cabinet is a valuable skill to have. Please leave any questions or suggestions you have in the comments section below.