If it weren’t for controllers, then video arcade games would be nothing more than fancy film kiosks. Controls are what make games interactive, so if they don’t work properly, then a game becomes a really large and expensive paperweight.
Fortunately, most controls are very easy to troubleshoot and fix, which is what we will cover in this edition of Tech Tips. If you are looking for other categories, click on this page and scroll down a little to find other maintenance and tech support focused articles.
How Do Controllers Work?
To start off with the basics. There are a lot of different controllers that have been developed for the arcade industry since the early 70s, including joysticks, steering wheels, foot pedals, light-guns, knobs/dials/spinners, buttons and so on. Most of these controllers function in one of two ways: as a digital (on/off) or analog (variable input) device.
For a typical digital controller, the joystick or button pushes against a microswitch that has been wired to a 5v line. Kind of like a light switch. It’s on or its off. When you push up on the joystick, a microswitch gets pressed, which causes the circuit and 5V to be completed, thus registering as “on.” The prong on the bottom is always the ground; games will then use one of the two prongs for the input (if it doesn’t work on one, try the other. For most games, it’s the straight bottom front prong).
For a typical analog controller (joystick, steering wheel, gas pedal) the switch is called a potentiometer, which is also wired to 5V power, but tends to have three wires connected to it. When the wheel or controller moves, it changes the voltage inside of the device, which is interpreted by the game as a number and thus a position. This is reported to the game, allowing for a finer degree of control than a joystick does. Steering wheels in arcade games are always an analog device, sensing the position of the wheel based on the number that the potentiometer is reporting.
There have been variations on switches and analog inputs, including leaf switches (no click, just a smooth feeling), optical switches (Infrared sensor that detects if the IR light is being blocked or not), and hall effect sensors (magnetic sensing), but our main focus here will be on the most common types of inputs, the microswitch and potentiometers mentioned above.
Issues with microswitches:
Regardless the type of controller, if it uses a microswitch, then troubleshooting it is going to be the same. Here are the things to check for:
- Are the input and ground wires properly connected to the switch? Are grounding wires properly grounded?
- Is the controller making proper contact with the switch?
- Is there any damage to the wire(s)?
- Have you connected a different working switch to the same wires and tested?
Often the failure to a switch is because of wiring – it’s loose, it’s been damaged (due to a pinch or overheating), the wiring has become frayed, or it’s been connected to the wrong part of the switch. It is generally simple to test the input wire and the ground on another switch that you know works. If the switch works there, then it’s a bad switch. Otherwise, it can be the wire. If there is damage to the wire, find out where and cut past that point, strip the insulation with a wire stripper, then attach a new crimped connector, or crimp a new wire to it to reach the switch.
In terms of wiring, it is best that wires be crimped with the correct type of connector. Soldering wires straight to one of the microswitches leaves/prongs can work, but those tend to deteriorate over time due to heat.
Issues with potentiometers:
Steering wheels, foot pedals and some joysticks use potentiometers (often just called “pots”) to detect where the controller is positioned. Steering wheels will use just a single pot, while analog joysticks will often use two.
If one of these controls isn’t working properly, then you need to look at the potentionmeter.
These devices will often have a gear or other attachment on them, which is fixed into place with a small bolt. Often this bolt is tightened using a small key key. To remove a potentiometer, you need
Potentiometers have three prongs that need to be connected to the inputs. Note that coloring is not standard across all games, so please refer to the game manual, or see what the pattern was to the potentiometer before removing/replacing the wires.
Common problems include:
- Bad calibration
- Faulty wiring
- Loose or misaligned gear attachment
- Lack of lubrication (only in certain games – most of the time grease or oil is not used)
The calibration is handled by the game itself; how to calibrate depends on the precise game and tends to be accessed from the Service Menu. Also ensure that the gear attachment is tight, as a loose attachment will result in poor or no operation.
If the wiring is properly connected but the potentiometer doesn’t calibrate, it might be worn from age or simply faulty. Replace with the same type of potentiometer.
Note that if a game is using mounted guns (examples include Deadstorm Pirates, Jurassic Park, The Walking Dead, Let’s Go Island, Halo: Fireteam Raven, etc.), then these guns employ the use of two potentiometers (one for horizontal movement, the other for vertical). While the issues laid out above will apply, it needs to be kept in mind. There can also be an issue with the gears that these potentiometers attach to – if a pot checks out but is still not calibrating, check the plastic gear that it is supposed to be connecting with and ensure that it is in the correct position and tightened.
Issues with IR sensors:
Ok, we will cover Infrared sensors very quickly. These are often used in pinball machines and in some modern light-gun games. Note that this is only the case for gun games that have free guns with modern flat panel displays (Big Buck Wild, Aliens Armageddon, Target Bravo: Operation GHOST; etc.)
If a light-gun is not aiming correctly on the screen, the first thing you should do is go into the game’s calibration mode and go through that. On older games, calibration can be hampered by the display settings (distorted image or too dark a screen), so make sure that the display is properly operating before you calibrate.
If that doesn’t fix it, then it can be an issue with the IR sensor net that is typically located within the marquee area, behind tinted black plexiglass. You can see if the IR sensors are working or not by going into the camera on your phone and pointing it directly at the sensor net. You should see a number of purple lights that are not visible to the naked eye. If all of the lights are bright, then they are fine. If you have dim or completely dark lights, then the IR sensor or the board needs to be replaced.
If the IR sensors check out, and you have no reticle on the screen, then check the USB connection. Sometimes this needs to be moved, reset (pull out, put back in). But also keep in mind that many games that use USB use the front USB ports on the computer, and they will not work if you plug it into the rear ports.
If you are still having issues, then it might be the camera in the gun. Guns in these instances feature a camera that can “see” the IR lights. Replace the camera and see if that resolves the issue. If not, then it could be the circuit board inside of the gun itself.
That covers the essentials of arcade controls. If you’ve missed our other tech tips articles, then be sure to check them out here!