While replacing a plug on a power cord can fix some issues, there might be times when you find that the cord itself is causing problems. Frayed and exposed cords can lead to inconsistent power issues with your arcade cabinet that can cause the parts inside to break down earlier than expected. In this post, we will discuss how to replace the power cord in your cabinet to ensure that your game is getting consistent power.

Replacing A Power Cord

http://www.youtube.com/watch?v=kaBJ-Dpw9Qc

If you read our previous post on Replacing A Plug On A Power Cord then you are probably somewhat familiar with working on power cords. Most of the power cords that you encounter will have three wires inside of a black sheathing. These wires are typically color coded with the black wire representing AC line (sometimes called live, load or hot), the white wire representing AC neutral and the green wire representing the ground. For wires that are not color coded, you can determine the line and neutral from the plug. The wider prong on the plug should represent AC neutral (or white wire) leaving the smaller prong to represent the AC line (or black wire).

Once we have determined what the wires represent in our current power cord, we can remove it from the cabinet. Instead of cutting the old power cord and splicing the new one into it, we recommend tracing it back to where it connects inside the cabinet. A common point of connection for power cords is an AC filter. These filters look like small, silver boxes that usually have three prongs that protrude from the bottom and two that protrude from the top. Each prong corresponds to one of the wires in our power cord. Usually the left prong will be the AC neutral, the center prong the ground and the right prong the AC line. In order to remove the power cord, we must desolder these wires from the AC filter.

Sometimes the wires might not be connected directly to the AC filter. For instance, the cabinet in our video has the black wire going through a fuse before it gets to the AC filter. In this case, we want to desolder the black wire where it connects to the fuse and leave the wire going from the fuse holder to the AC filter. This fuse can provide protection in the event of a power surge so it is best to leave it in there. Also, the ground wire in our video is connected to a braided wire that runs throughout the game instead of the AC filter. This is fine as long as we connect the ground wire from our new power cord to the same place in the cabinet. Please see the image below for more information.

Click Image To See A Larger Version

When you have removed the old power cord from the cabinet, we can install the new power cord. This basically just entails soldering the new power cord wires to the locations where we desoldered the old power cord wires. To make the installation your new power cord easier, we recommend getting one that comes with the sheathing partially removed from the end and the wires exposed. Once you have finished soldering your new power cord into your cabinet, your arcade game should power up without any issues.

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Inconsistent power issues can wreak havoc on the parts inside your arcade cabinets. Replacing frayed and exposed power cords with new power cords can help to ensure that your arcade games stay working for years to come. Please let us know if you have any questions or suggestions by leaving them in the comments section below.

While most standard arcade games run 120 VAC to the various parts inside the cabinet, Nintendo arcade games are somewhat different. Nintendo is a Japanese company and as such uses the Japanese AC voltage specification which is 100 VAC. This difference may seem small at first glance but it can wreak havoc on your repair and restoration efforts. In this post, we are going to discuss some tips to keep in mind when working on Nintendo arcade games.

Working With Nintendo Arcade Games

http://www.youtube.com/watch?v=fVhbEbdlFNs

When you look into the back of your Nintendo arcade cabinet, you might think that it looks pretty much the same as any other cabinet and you would be right for the most part. The main difference is that the power cord runs to a transformer that converts our 120 VAC from the wall to 100 VAC for use inside the cabinet. Most everything inside the cabinet derives it’s power from this transformer. This includes the monitor (or monitors if you have a dual screen), power supply and even the marquee light. Also, some of these cabinets have power plugs in the bottom. Be very wary of these plugs as they also tend to put out 100 VAC which can cause problems with anything you plug into them (such as tools).

You might have heard some horror stories of people trying to replace an arcade monitor in a Nintendo arcade cabinet with another major brand such as Wells-Gardner. This is because most monitors here in the states are made to take the 120 VAC instead of the 100 VAC and will not receive the correct power depending on how you hook them up. In the video for this post, we have a similar dilemma with a power supply. The best way to guarantee that you are getting 120 VAC to the parts that require it is to tap into the power cord itself.

The easiest way to tap into the power cord on many Nintendo arcade games is to locate the connector between the power cord and the transformer. From here you can use a pin pusher to remove the pins from the connector. You can then cut and strip these wires to get them ready to be repinned. Take some spare wiring and twist it together with the existing wires you just stripped from the connector. It is a good idea to use the same color wires to tie into with so that you can keep your AC lines consistent. Once that is done, repin the wires and insert them into the connector. Reconnect the connector and you should now have two wires protruding that contain the 120 VAC necessary to power the non-Nintendo parts in your arcade cabinet.

Nintendo has made some great arcade games over the years. From Donkey Kong to Playchoice 10, seems like everyone either owns or has wanted to own one of their great classics. Just keep in mind that the power scheme that lies within them is foreign and as such can be difficult to work with sometimes. Knowing up front that Nintendo arcade games run off of 100 VAC instead of the standard 120 VAC will save you a lot of time in your future repair endeavors. Please feel free to leave any questions or suggestions in the comments section below.

While switching power supplies are the standard in newer arcade games, classics such as Ms. Pac Man and Centipede originally had non-switching, linear power supplies that can be quite intimidating at first glance. These classic (or old school) power supplies usually look like a brick located at the bottom of your cabinet and can be difficult to work with due to years of wear and tear. In this post, we will discuss how to check the voltage coming out of your classic power supply as well as how to check the voltage on your board at the harness connection.

Checking A Classic Power Supply

http://www.youtube.com/watch?v=Vys-s1cTT6g

First off, we want to identify where our classic power supply is in our cabinet. These power supplies are typically located at the bottom of the cabinet and resemble a brick-like structure. They should have AC voltage coming into of the bottom of one side either directly from the wall or from an AC filter. The opposite side should contain the AC voltages that go out to the board and other cabinet parts such as coin lights. Be careful not to mistake your isolation transformer with your power supply. Isolation transformers can look very similar to classic power supplies except for the fact that they usually have two wires coming into the bottom for AC input from the wall or AC filter and two coming out of the top (usually on the same side) for AC output to the monitor.

If you just see one brick-like structure in the bottom of you cabinet it could be that you have a dual power supply/isolation transformer unit. If this is the case then the bottom of both sides should have AC input lines with the top of one side putting out multiple AC voltages to the board and the top of the other side putting out AC voltage to the monitor. While these dual units are not as common, they are certainly something to be aware of in case you run across one.

Once we have located the power supply in our cabinet, we can begin the process of checking the voltages. Let’s start off by setting our multimeter to the AC voltage setting. Now we must identify which of our contact points are grounds and which ones hold voltages. Our ground wire in the video is indicated by a 0V (Zero Volts) marking on the power supply label. Most of these power supplies were labeled at one time or another, however, age and normal wear and tear usually leave them in an unreadable state. If you cannot identify which wire is the ground wire, we recommend placing the black probe of your multimeter on the AC ground coming from the wall. This AC ground is usually easier to locate (it’s usually the green wire on the AC filter) than the AC ground on the transformer and allows us to check the contact points safely with our red probe. This is a much better alternative than randomly touching contact points to see if we can locate the ground wire.

Something to keep in mind when checking our classic power supply is that not all of them put out the same voltage. For example, a Ms. Pac Man usually puts out 7 VAC while other games might use a higher voltage because of the other cabinet parts that use that particular line. If you find that your power supply is giving off higher voltage than what the manual for the game shows then you might try checking the voltage where the board connects to the harness. This can usually be accomplished by finding the ground and AC voltage pins on your harness (via your manual) and placing your multimeter probes on these points. Your board might have easily accessible contact points that you can place your probes on for testing. Whatever way you decide to check the voltage going to your board, performing this check allows you to make sure your board is not just getting power but the correct voltage.

You might also notice some fuses located in the bottom of your arcade cabinet around the power supply. While you can certainly check these in the traditional manner that we discuss in our post on Checking Fuses With A Multimeter, you can also check them with the game on by placing your black probe on a ground point and the red probe on the other side of the fuse. If voltage is flowing through the fuse then you know that it is good. Also, make sure that you are careful when working with an arcade game that’s plugged in. Always take the necessary measures to make sure you are safe when working in these situations.

Like we discussed in our post on Checking And Replacing A Power Supply, most arcade boards use DC power. Before switching power supplies became popular, different arcade manufacturers would use different methods to convert the incoming AC power to DC. For example, a Ms. Pac Man board takes in AC power from the power supply (or transformer) and converts it to DC voltage for use by the logic circuits and audio amplifier. Of course, you can also hook up DC voltage directly to the board so that the board does not have to convert it. As you can see from these Ms. Pac Man pinouts on MikesArcade.com, there is both an AC and DC wiring configuration. Many Atari arcade games such as Centipede have an AR (Audio Regulator) board that regulates the voltage coming in from the power supply then passes it along to the main board. The AR board also acts as an audio amplifier for these games and can be the cause of audio problems you might be having with your Atari arcade games. The AR board should have test points on it that allow you to check to see if your voltage is correct. If you suspect that your AR board might be having issues, Bob Roberts sells repair kits that can restore it’s functionality.

Most of the arcade games that people consider classics such as Ms. Pac Man and Centipede did not have the benefit of switching power supplies when they were produced. As such, having the skills to check a classic power supply can be a very valuable as you work on these older arcade games. Please let us know if you have any questions or suggestions by leaving them in the comments section below.

Back when arcade games first came out every game had a different wiring scheme which made trying to swap a board from one game to another a very difficult task. This problem compelled the arcade manufacturers to get together to create a standard and thus the JAMMA standard was born. In this post, we will help you get familiar the JAMMA standard.

Getting Familiar With The JAMMA Standard

http://www.youtube.com/watch?v=poL25IlGT_w

Before we get started, I would like to mention that I have posted a printable version of the JAMMA pinouts for your convenience. This will come in very handy if you are dealing with JAMMA at any point in the future. Please click the link below to access this document.

http://www.arcaderepairtips.com/jamma.html

JAMMA is a wiring standard that was developed to make switching arcade boards from one arcade cabinet to another easier. JAMMA stands for Japanese Arcade Machine Manufacturers Association and was developed in 1985. Any arcade game that predates this will not be JAMMA and even some games after this are not JAMMA. We recommend checking your manual or the internet before assuming that your arcade board is JAMMA.

A JAMMA harness is composed of a 56-pin connector (28-pins on each side) with wires coming from each of the pins. There are two sides of a JAMMA connector: the parts side and the solder side. The parts side of your board contains all of the surface mounted components while the solder side just contains traces and solder dots. It is important to identify which side is which so that you don’t plug your board in the wrong way. As luck would have it, many JAMMA connectors are labeled so that you can easily identify which side is which along with what each pin goes to.

If your JAMMA connector is not labeled with the pinouts, your first task will be to identify where pin 1 is located. The easiest way to located pin 1 is to use pin 7 which is known as the key and is usually blank. Once you have located pin 7, you’ll noticed that it divides the harness in two 2 halves. The shorter half (pins 1-6, A-F) should contain pin 1 along with all of the wires that go to your power supply. While these wires usually go straight from the power supply to the board, you might notice that someone has jumpered off of them to send power to another part of the cabinet. This is fine and a common practice.

As we look at the longer half of the connector, you will notice some wires going to the monitor. These wires (pins 12-14, N-P) are used to send the display signal to the monitor. There should be a wire for each of your colors (red, green and blue) along with a sync wire and a ground wire. If we look further down the connector, we will find the wires for our joysticks and buttons (pins 17-26, U-d). All JAMMA harnesses support 2 players, however, they might not have the all wires hooked up for each of them. Games that have more than 3-5 buttons per player or more than 2 players usually require a kick harness to work properly. A kick harness is an extra harness that attaches to the board along with the JAMMA harness to allow for the extra inputs.

You might also notice that there are not enough ground wires located on the connector to wire up all of your arcade controls. In this case, you will need to use a technique called daisy chaining. Daisy chaining is a wiring scheme that consists of jumpering a wire off of each connector so that the ground signal will carry over to the next connector. We’ll talk more about daisy chaining when we talk about control panel wiring.

JAMMA wired arcade cabinets take the work out of switching boards between cabinets. In face, the majority of the arcade games that you see today are wired using the JAMMA standard. Knowing the JAMMA standard will carry you far in your arcade repair endeavors. Please leave any questions or suggestion in our comments section below.

When you get your arcade game home for the first time, you might notice that your power plug is in rough shape. Frayed wires, loose connections and missing ground prongs are just some of the issues you might encounter. In this post, we’ll discuss how to replace a plug on a power cord so that you can ensure the playability and safety of your arcade game.

Replacing A Plug On A Power Cord

http://www.youtube.com/watch?v=HAzTC1TFqyQ

Let’s start off by determining if we should replace the power plug or not. Obviously if our plug is in good shape we don’t want to take valuable time to replace it. A couple of things to look for when making this assesment are exposed or frayed wires, missing or bent progs (including the ground prong) and loose connections. Please see the image below for some good replacement candidates.

Once you have determined that your plug is damaged, we can now begin the process of replacing it. Let’s talk about what tools you will need. You will need a screwdriver (phillips or flat depending on your plug), a pair of wire cutters and a pair of wire strippers. We have also found it helpful to have a pocket knife or razor blade handy in case you have to cut the jacket (or outside cord wrapping). If you have any other questions about these tools please refer to our post on Your First Arcade Toolbox.

Now that we have assembled our tools, let’s move on to removing the original plug. Depending on the shape your current plug is in, you might be able to remove it without cutting the wires. We recommend removing your plug this way but there is no harm in just cutting it off either. With the plug removed from the wires, start to inspect the wires for any damage. You might have to cut your wires back further down the cord if they are currently damaged near the end. Once you are satisfied with your wires, remove the insulation and strip the wire ends. We have now successfully prepared our cord for our new plug.

When you have completed removing the original plug and preparing your wires, we can move on to installing our new plug. New plugs can be purchased from a variety of places. We typically purchase our plugs from Home Depot where they run around $5 a piece. Wiring up your new plug is pretty simple. Most of the power cords you are going to encounter have 3 color coded wires: a black wire (hot), a white wire (neutral) and a green wire (ground). The plug that you bought might tell you where to put each wire but if not it should be indicated by different color screws. A copper/bronze screw is typically for the black wire, a silver screw is typically for the white wire and the green screw is typically for the green wire. Insert the correct wires under each of the correct screws and screw each wire down using your screwdriver. Once you have done that, close up your plug enclosure and you are done.

Replacing an old, damaged plug with a new plug is an easy repair that can prevent damage to your arcade game in the long run. It also prevents electrical shocks to people plugging in the game and perhaps electrical fires from shorts in the wiring. Please feel free to leave any questions or suggestions in the comments section below.

With most current arcade games being powered by computers, arcade cabinets can get quite hot these days. Making sure that you have adequate cooling in your cabinet can help prevent your game from overheating. In this post, we’ll discuss how to install a fan in your arcade cabinet so you can increase the longevity of the components inside.

Installing A Fan In An Arcade Cabinet

http://www.youtube.com/watch?v=JePurpFQ6Kk

First, we must decide what size and type of fan that we want to use. We typically like to use a 4″ fan that uses either 5 or 12 VDC. Since DC voltage is commonly used in arcade games, it is usually easy to locate some power wires to tie the fan into. Also, we recommend getting a fan that has ball bearings if you are worried about the noise level of the fan in your cabinet.

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Let’s take a moment to discuss the concept of cooling. It is the job of a fan to move air through your cabinet. The idea is to draw cooler air in and exhaust warmer air. Most of us learned in high school that hot air is less dense than cold air which causes it to rise. So if you install a fan in the bottom of your cabinet, you probably want that fan to draw the cooler air in. Conversely, if you have a fan at the top of your cabinet, you probably want that fan to exhaust the warmer air out.

With the concept of cooling in mind, let’s pick a location for our fan. The most important thing is to make sure you pick a location where you can easily wire up power to the fan. A fan is no good unless you can get power to it. It’s also good to place your fan somewhere inconspicuous where it doesn’t interfere with other components in your cabinet. If you have small children, make sure that it is difficult for them to gain access to it. If the fan exhausts out, make note of what it might be blowing on. Some people don’t like hot air blowing on their legs.

Once we’ve picked a location, it’s time to trace the fan. With the fan in place, take a writing utensil and trace around the fan. Please note that we will not be cutting out this line. This is just to give you an idea of where to cut your ventilation hole. We typically use a 4″ hole saw with a corded drill to cut our ventilation hole out. Line up the hole saw in the middle of our traced outline of the fan and begin to drill till you have made it all the way through the material you are cutting. You have now successfully made a ventilation hole for your fan.

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After we have cut our ventilation hole, we can now mount the fan into place. Place the fan inside the traced area we marked before we drilled our ventilation hole. If you have a fan cover, place it first before the fan. Take some screws and screw the fan down to the cabinet. Remember to get screws that are long enough to go through the screw holes on the fan and make contact with the cabinet. You have now successfully mounted the fan in your cabinet.

With the fan mounted, we must now wire power to the fan. Take the wires coming from the fan and strip them. If you are getting voltage directly from the power supply we suggest putting the fork type terminals on the ends. These easily slide under the screws of most switching power supplies. Once you have wired up your fan, you are ready to test. Plug the game in and see if you have a spinning fan. If your fan spins then you have successfully installed a fan in your arcade cabinet.

Before we finish our project, you might want to place either gutter mesh material or a perforated aluminum sheet over your fan to keep people from putting objects in it. This also has the added bonus of making your fan installation job look more professional. You can get these items at most major hardware stores. It’s not a necessity that you do this but it does add a nice finishing touch to your project.

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Installing a fan in your arcade cabinet can increase the longevity of your arcade components. Keep your cabinet cool and it should help you enjoy your arcade game for years to come. If you have any questions or suggestions please post them in our comments section below.

While marquee and coin lights do not effect the gameplay of an arcade game, they do provide a more authentic arcade atmosphere and experience. In this post, we will discuss the steps that you can take to troubleshoot your arcade lighting issues.

Replacing Lights In An Arcade Cabinet

http://www.youtube.com/watch?v=IZQI5nOHI5w

Before we get started, we would like to thank all of you that gave your hard earned money to our HD Camcorder fund. Through your generous contributions we were able to purchase a new pocket camcorder with high definition capabilities. This post contains the first video that we’ve shot with the new camera and the results seem to be very good. Thanks again and enjoy our new high definition videos.

The first type of arcade lighting that people think of is typically the marquee light. This is the light that acts as a backlight for the glass or plexiglass marquee. In most games, florescent light bulb fixtures are used; however, older games such as Pac Man have regular filament light bulb fixtures. We prefer florescent light bulbs as they are brighter and tend to give your marquee a much better look when lit up.

Getting to your marquee light fixture in most arcade games is pretty simple. You can start off by removing the marquee. The marquee typically has two metal pieces of angle iron that are screwed into the cabinet that hold it in. Unscrew either the top or the bottom piece and remove it and the marquee from the cabinet. This should give you access to your marquee light fixture.

Once we have access to the light fixture, we can start our troubleshooting. We usually start off simple by trying to replace the bulb. If you replace the bulb and it still doesn’t work, check the wiring going to the marquee light to make sure you are getting power to the fixture. If it is a florescent light fixture, you can also try replacing the starter which is a round metal piece that looks like a capacitor. Just twist it out of the holder and take it to your local hardware store to find a suitable replacement. If a new starter doesn’t work, we usually just buy a new fixture. We highly recommend ordering your florescent light fixtures from twistedquarter.com. They sell the newer style florescent light bulb fixtures for about $10. A very good deal from an excellent retailer.

Now that our marquee light is working, lets move on to our coin and button lights. You can gain access to your coin door lights by opening your coin door and taking a look at the lights behind your pricing labels. If they are not working, take them out and give them a good inspection. If they look burnt, see if they have a number on them before throwing them away. This number will help you identify what type of bulb you need to replace them with. The most common bulbs are typically 161 for 12-14 VDC and 555 for 5-7 VDC. Please check out the chart below for other bulb numbers and their voltages.

If you suspect that you have bought the wrong bulbs, an easy way to tell is by the brightness of the bulb. If the bulb is super bright then your bulb’s voltage rating is lower than the voltage going to your socket. The same goes for if your bulb is super dim except for that your bulb’s voltage rating is higher than the voltage going to your socket. You can, of course, always check the lamp sockets with a multimeter to find out the voltage.

Push button lights use the same type of holders and bulbs as the coin door lights except for they clip behind a push button. These lights are usually removed by either pulling or twisting the holder from the back side of the push button. You can check the voltage just like you did with the coin door lights. If you don’t get a voltage reading then check your wiring. You can also check to make sure you have the voltage wires and not the push button wires.

A well lighted arcade cabinet typically increases the number of plays you get in an arcade and gives your cabinet a more authentic feel. Please let us know if you have any question or suggestions by posting in our comments section below.

Molex connectors can provide a handy way to easily remove or replace items (such as a monitor chassis or control panel) without rewiring. In this post, we’ll discuss how to install a Molex connector into your preexisting arcade cabinet wiring.

Installing A Molex Connector

http://www.youtube.com/watch?v=Ftm_oSztTrA

Most people tend to use Molex as a term for any and all types of connectors, however, Molex is actually a brand of connector. The brand Molex has become so popular that, like Kleenex, it has become the name by which all connectors are called. Molex connectors are great to use in places where you might have to disconnect wiring in the future as it eliminates the need to rewire and solder. Today, we’re going to discuss how to install a Molex connector into your arcade monitor power cord.

Before we get started, it’s important to have the Molex connectors and pins you’re going to use on hand. For this job, we will be using size 0.93″ Molex round pins and 2 pin Molex connectors. There are more sizes (such as 0.100″ and 0.62″) and types (such as flat) available but we have found that 0.93″ is easier to work with for jobs that require round pins. Make sure you order both male and female Molex connectors and pins as you need both to make the connection.

Once we have our Molex connectors, we can begin our project. Take the wires that you want to place the Molex connector on and strip them about 1/4 of an inch from the top. This should give you enough wire to make a good connection with the Molex pin. Pick up your D-Sub Pin Crimper and one of your Molex pins. Place the pin in the correct slot of your crimper with the open part of the pin towards the floor. A good way to remember this is to use the tee pee and indian analogy from the video. It sounds silly but it really does help you remember.

Now that you have correctly placed the pin in your crimper, place the wire you stripped earlier into the open end of the pin and then squeeze the crimper. It’s good to squeeze the pin using the crimper a second time from a sideways position to make sure that it’s making a good connection to the wire. This is known as Tim’s Patented Double Squeeze method.

Let’s now place our Molex pin we crimped into the correct Molex connector. Take a look at your pin and see if it’s male or female. A good rule of thumb when placing your pins into connectors is to place female pins into the male connector and vice versa. While this is not a requirement, this is a very common configuration. Push your pin into your connector and you should hear a snap. This snap indicates that the pin has been successfully installed. If you do not hear the snap, you can take a small flat head screwdriver (such as a jeweler’s screwdriver) and push on the pin until you hear it snap.

If you screw up on a Molex connector or if you just need to repin it, you can use a Molex pin extraction tool. The Molex pin extraction tool allows you remove the pins from a connector without damaging the connector or the wire. You can order it from the Amazon.com link below. To use it, push the extraction tool into a connector with a pin in it and gently pull on the wire connected to the pin. The pin should pop out of the connector allowing you to repin the wire. The alternative is to cut the wire but you might have limited length to work with.

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Installing Molex connectors is a valuable skill for any arcade repair technician to have. For more information on Molex connectors, please visit http://www.marvin3m.com/connect/index.htm. Please feel free to leave any questions or suggestions below.

Power supplies are a great starting point if you are trying to troubleshoot problems with your arcade machine. Bad voltage can cause a variety of problems that can sometimes be mistaken for a bad board. In this post, we’ll talk about how to check a power supply for the correct voltage as well as how to replace a power supply should it go out.

Checking And Replacing A Power Supply

http://www.youtube.com/watch?v=idievP6zuyY

Before we get started, it’s a good idea to unplug your monitor and board from the power supply. If our power supply is bad, we don’t want it to damage anything in our cabinet. Also, if the power cord on your arcade game is missing the ground prong, you should think about replacing it. The ground prong gives you protection against shocks that might occur due to electrical issues. With that said, let’s plug in your arcade game, turn the power switch on and get started.

In order to check the voltage on your power supply, you will need to use a multimeter. Multimeters have several modes; some of which we have talked about in previous posts. The two modes we are going to talk about here are Alternating Current (AC) voltage (VAC) and Direct Current (DC) voltage (VDC). Some multimeters have several different settings for AC voltage and DC voltage. You always want to set the multimeter on the first voltage setting that is greater than what you are trying to test. For instance, if you’re trying to test the AC voltage coming out of a plug, a good setting would be 200 VAC as AC voltage in the United States is usually between 110 and 130 VAC.

With our multimeter now set to VAC, let’s check the AC voltage coming into our power supply. Place one of your multimeter leads on each of the terminals marked AC on your power supply. As we stated before, you should read somewhere around 120 VAC. If your multimeter does not read around 120 VAC, it’s time to start tracing down your wiring to see what the problem is. A reading of 0 VAC is a good indication that there is no AC voltage going to your power supply. Check the connection between your main arcade power cord and your power supply to find the problem. If your voltage is not around 120 VAC, check your wall plug to make sure it is reading correctly. If it reads correctly, check for items inside your arcade cabinet that might be causing power issues.

Now that we have checked your AC voltage and verified that it was correct, we can now test your DC voltage. DC voltage is what powers your board, controls, and coin door lights among other things. In order to test our DC voltage, we need to set our multimeter to VDC. We will be checking voltages around 5 and 12 VDC so a good setting on your multimeter would be 20 VDC. Once you have your multimeter set, it’s time to test our 5 VDC. Place your black lead on the common (or ground) terminal and place your red lead on the +5 VDC terminal. You should get a reading that’s around 5 VDC. Keep that reading in mind while we test the 12 VDC. While keeping your black lead on the common (or ground), move the red lead to the +12 VDC terminal and keep this number in mind as well.

After reading the 5 VDC and 12 VDC, you might realize that these numbers are a little bit higher or lower than what they are suppose to be. You might have noticed a knob on the power supply. This knob controls the DC voltage output. Turning the knob right or left can increase or decrease the amount of DC voltage coming out of the power supply. Turn this knob to the right or left and test your 5 VDC and 12 VDC to see if they are closer to the correct voltage than before. If you are coordinated, you can test the voltage while turning the knob but either way should be fine. Once you are satisfied with the DC voltage output, turn the arcade game off, plug in your board and turn it back on.

If you try and turn the knob but you can’t seem to get both the 5 VDC and 12 VDC close enough then you might need a new power supply. You can buy power supplies from our favorite parts distributor: therealbobroberts.net. Replacing a power supply is easy. First, make sure the game is unplugged. Then, remove the wires from the terminals on the existing power supply and place them on the matching terminals of the new power supply. You might want to label the wires as you take them off so you can make sure you put them on the correct terminals of the new power supply. Placing the wrong voltage on the wrong terminal can have dire consequences for your arcade game! Once you have done this, you have successfully replaced a power supply.

It is important to note that some power supplies today don’t have terminals and instead are connected to the board by a Molex connector. If this is the case with your power supply, you can still check your DC voltage by using the black wire as your common (or ground) wire, the red wire as your 5 VDC, and the yellow wire as your 12 VDC. Just follow the exact same steps above except put your leads into the connector instead of on the terminals. You might also notice that your power supply has a -5 VDC. While this isn’t used much in newer games, you can still check it. Just use the same technique that we used with the 5 VDC and 12 VDC terminals. The -5 VDC is usually indicated by a white wire on a Molex connected power supply.

Many strange problems that you encounter in arcade repair can center around the power supply. It’s always a good place to start if you’re not sure what the problem could be. Please let us know if you have any questions or suggestions by leaving some comments below.

Checking fuses with a multimeter can be a simple, yet effective way to fix an arcade game that’s having power issues.

Checking Fuses With A Multimeter

http://www.youtube.com/watch?v=VAS3C-c22KM

Before you touch anything in the arcade cabinet, make sure the power is switched off and the game is unplugged. In most arcade games, the fuses are located at the bottom of the cabinet near the power supply. Make sure you remove the fuse from the clamp before you test it as testing it in the clamp can sometimes generate a false good fuse reading.

To test the fuse, place your multimeter on the continuity test mode icon (also known as the diode test icon). The icon should look like this…

Continuity Test Icon

Then, take your probes and touch them to both ends of the fuse. A good fuse reading will generate a beeping sound or will read 0 (ZERO) ohm. Of course, any other reading on your multimeter (including a blank reading) indicates a blown fuse reading. If you get a blown fuse reading, make sure you replace it using only the same current and voltage ratings as the original one. These ratings are usually indicated on the fuse itself. If you replace the blown fuse with a working one and the game blows that fuse as well, check your power supply and wiring for issues before replacing it again.

The ability to test fuses will carry you a long way in repairing not just arcade games but electronics in general.  This is often one of the most overlooked parts of arcade game repair so make sure that you check your fuses before moving on to more advanced troubleshooting.