Sound has been an integral part of the arcade experience since the beginning. Sounds like the waka waka waka from Pac Man and the background music from Space Invaders have become staples in our popular culture. When people play an arcade machine, they expect to be immersed in these sounds as part of the experience. If the sound on your arcade cabinet is not working properly, it can lead to a frustrating experience for the player similar to trying to play with a broken joystick or button. While not all arcade games are exactly the same when it comes to their sound configuration, there are many common elements found among them. In this post, we will discuss how to troubleshoot some common sound issues with arcade games.
Troubleshooting Games With Sound Issues
Let’s start off our repair by trying to locate the volume potentiometers in the cabinet. Potentiometers (or pots) are knobs that can be adjusted to modify certain electronic aspects of your arcade game. Along with volume adjustment, potentiometers are also used on arcade monitors to adjust certain attributes of the picture such as position or size. Some common places for volume potentiometers include inside your coin door or on the game PCB (or Printed Circuit Board) in your arcade cabinet. Please keep in mind that the location will vary from cabinet to cabinet. Once you have located the volume potentiometers, try to turn them to see if it restores the missing audio. If there are multiple potentiometers for volume, you may need to turn them all up in order for it to make a difference. Some cabinets may not have a physical volume potentiometer for you to adjust. If this is the case with your game, consult the manual to see if there’s a way to adjust the volume using another method such as the test/service menus.
Sometimes the volume setting may not be the problem. It could be that the board itself is not putting out any sound to the speakers in the cabinet. A good way to test this is to get another game PCB that’s compatible with the cabinet and swap it in place of the current board. This is a great way to troubleshoot cabinets that are wired using the JAMMA standard as there are several compatible boards available. Using this method will help us determine whether the problem is with the game PCB or with the cabinet itself. If we swap the replacement board in the cabinet but the sound issues continue then we must have problem with our cabinet. If the sound comes through loud and clear using the replacement board then we must have a problem with our original game PCB.
Regardless of whether or not you’re able to install another board in your cabinet to test the sound, it’s a good idea to check out the speakers and the wiring just to verify it is working properly. Start out by checking the wiring that runs from the harness (where your game PCB plugs in) to your speakers. You may need to check the pinouts for your particular game to determine which wires go to the speakers. The pinouts can typically be found in the manual for the game or by searching for the name of your game with the word pinouts on the internet search engine of your choice. If your game is a JAMMA game and doesn’t have a separate audio harness, your speaker wires should be located on pin 10. We recommend using the continuity test on your multimeter to verify the connection between these wires. To test the wire continuity, place one lead on the appropriate pin on the harness and the other lead on the corresponding speaker prong. Most multimeters will either beep or read 0 (ZERO) ohm to indicated that a connection is being made. Make sure that you test both wires going to the speaker as they are both required for the speaker to work properly.
Once the connection from the harness to the speaker has been verified, we can start to test the speaker itself. Start off by checking to see if the speaker is shorted. You can do this by using the same continuity test that we discussed earlier except this time we will place each of the leads on the prongs of the speaker itself. If the multimeter beeps or reads 0 (ZERO) ohm then you probably have a shorted speaker and will need to replace it. Another way to test the speaker is by checking the resistance across the prongs. This can be accomplished by setting your multimeter on the ohms setting (omega for those of you who study the Greek alphabet, looks like upside down horseshoe to the rest of us). With your multimeter set to ohms, look at the back of the speaker to see if you can find the ohms symbol with a number beside it. This number indicates the speaker’s resistance. Once again, place each of the leads on the prongs of the speaker itself and we should get a value that’s CLOSE to this number. Don’t worry if the number is a couple of ohms off, as long as it’s close to the indicated number on the back of the speaker you should be fine.
Of course, you could continue to have sound issues even after accomplishing all of the steps described above. At this point, you probably either have a problem with your game PCB not outputting the sound or a sound amp that’s malfunctioning. Before suspecting the board itself, check to make sure that it is getting the correct voltages from the power supply. Many game boards require that the -5 VDC line be hooked up in order for the sound to work properly. It could be that whoever wired your cabinet originally left the -5 VDC line unhooked because it wasn’t required for the particular game they had in the cabinet. After checking the power, look to see if you cabinet has a sound amp board in it. Many cabinets (such as showcase style cabinets) have dedicated sound amps that will go bad from time to time. These are usually quite easy to repair but can also be replaced if necessary. Some game boards will have a built in sound amp. If this goes bad, you will need to repair the board to restore the sound. Just a quick tip: sometimes replacing the caps on these boards will restore the sound as the caps are usually a part of the sound amp. Some older games have a separate sound board. If this is the case with your game, make sure you check all of the connections going from this board to the game board and consult your manual for additional steps you can take to repair the issue.
With so many different sound configurations, troubleshooting sound issues in arcade cabinets can sometimes be a frustrating process. Just remember that the key is to narrow down where the problem is located and do the necessary repairs to get it going again. Hopefully this post will help you in this procedure and allow you to get the sound working again in your arcade cabinet. Please leave any questions or suggestions in the comments section below.