Arcade Repair Tips - Checking And Replacing A Power Supply

Uploaded by varcadegames on 20.07.2009

Hi, welcome back to the Arcade Repair Tips Video Series. Today we're going to talk about
how to check and maybe replace a standard switching power supply. First thing we're
going to do is we've got a Big Buck Hunter game here and we're having some video issues
so before we do any kind of board or monitor repairs or go into any detail on that we want
to make sure that the power supply is working and doing its job. Without the power and the
right voltages going to your boards, then you're not going to get the game working right,
good pictures, a lot of different problems it can cause. If we ever buy a used game,
we go to an auction or whatever, first thing we're going to do a lot of times. Right now
I've got the mother board unplugged, I got the monitor unplugged. Before we go into any
of that, we want to check and make sure that the power supply is working.
A lot of you have probably posted or said, "Hey, my game's giving me problems." A lot
of guys say, "Hey, check the voltage." What are they talking about? Well, what they're
talking about is you basically have your wire that goes into your game, then it goes around.
This is AC, alternating current, which goes all throughout your house. In other words,
it alternates everywhere.
What we're going to do is, this is a switching power supply which switches that AC or alternating
current to direct current. In other words, it goes straight to a certain thing and does
a certain function. We have a lot of voltage going in and maybe a small voltage coming
out. Most of your games run on 5 and 12 volts. Also some -5. So there are not a lot of things
you've got to know. You've just got to know what to check and when to check them.
First thing we want to do is you all purchased your meter and you got that ready. We're going
to put it on AC. We're looking for your common voltage coming from your house, around 110
to 130, 120 is about perfect. As long as it's 110. You start getting over 130, be careful,
ok? So make sure that the AC voltage coming in is fine.
On our power supply, it's labeled for me and most of them conveniently are. If you're not
sure, follow the wires back to what comes straight off of here. Generally on a wire
going in, you're going to have a black wire which is your hot, a white wire which is your
neutral, and then a green wire which is your ground. We want to really make sure that your
game is always grounded. So look at the plug. You know, when you get a game and you buy
one, look at your plug. Make sure that this long pin, the straight pin, the ground pin.
If it doesn't have one, throw that cord out and either replace it with another cord or
go and get an end and make sure of that ground.
Check all your games. I know, people say, "Well I plugged mine in. It works fine." Don't
play around without stuff being grounded. I notice a lot of times at work we'll have
people that experience a mild shock sometimes when the game is not grounded on the coin
door. So make sure that your game is grounded.
What we're going to check is you have the two AC coming in and then you have the FG
or your ground. So what we want to do is put the two leads, we've got the meter turned
on to AC, put it on the two ACs. As you can see, we have 133 volts coming in. A little
high, but I think we'll be ok today.
Now what we want to do is switch it to DC. Remember, we're only looking for 12 and 5
volts. So you don't have to have it up on - my DC gives me a choice between 220 and
200. I'm going to put mine on the 20 right here. Now what you want to do is put the black
lead on the ground where it says ground on here. And then the red lead on either your
5 volts, which is here on my power supply, or over here on your 12 volts. You'll notice
that my 5 volts is about 5.23, which is ok but it needs to be a little lower. So while
holding them down I'm going to turn this knob up here. Sometimes you have to use a flathead
screwdriver or something. This one's convenient where you can turn it by hand. I'm going to
turn that down. Then I'm going to check the 12 volts, 11.41.
Ideally you want to get as close to 5.00 and as close to 12. I have mine turned all the
way down and I'm still running 5.23. And my 12 volts is only 11.4. Those are probably
acceptable ranges, but hey, we can get a lot closer than that. So maybe it's about time
to replace this power supply.
Here's a brand new one. All I'm going to do is unscrew these screws, unscrew those wires,
and put the wires where these were and screw them in. It's pretty simple. But if you don't
know where the wires go, it's pretty much labelled for you. You've got the AC line,
which will be your black wire, your AC neutral which is your white wire. This symbol right
here is a symbol for ground, or a lot of times it will have an FG or a big G or something
like that. That's your green wire. Then you have your -5, your +12. A lot of times instead
of the word ground, you'll see the word COM. It stands for common. You want to make sure
to put the black wires, or your common wires. Those come straight from your JAMMA harness
or look up your pin outs. You can get those there. Then here's your +5 which a lot of
times is a red wire. Don't go by wire colors though, go by where they go on your harness.
If you're not sure, email and ask us and we'll tell you how to do that. Maybe we'll do another
video on that one day. So you basically unscrew these, put the wires in, screw them back down.
If you have any questions though, be sure and email us.
Now some of you might say, "Well, my power supply doesn't look anything like this." A
lot of games now have this type, or the ATX. You know, sometimes I say computer-style even
though this would be a really big one for a computer. But they kind of look like one
that you've seen in a PC. These are really good power supplies. A lot of the newer style
games have them. They're a little higher amperage and stuff. Personally, on the multicades and
stuff, transferring a Pacman over to a switcher, I prefer this style. They're a little smaller,
easier to get in and all that stuff. But these are ok. There's not really that big of a difference
in them except for some of the 25" monitors and things like that, you'll see this style
in there. Basically you've got your power cord that comes in. Then you've got this big
Molex cord coming out with red wires, black wires, yellow wire and a white wire. Well,
all you do to check the voltage is to put it on DC. Put your black wire in where the
black wires are and put your red wire where one of the red wires is. That should be your
5 volts. Then the white wire should be your -5 and the yellow wire should be your 12 volts.
Now if they're not put in the right place or for some reason your wiring is different,
just keep that in mind. Whatever you plug into here though, if your red wire is showing
12 volts, make sure that's going to the 12 volts on your board.
Anyway, this is just kind of a basic overview, guys. I know you might have some questions
so by all means, email and be sure and ask us. We hope you've enjoyed this and we'll
talk to you more again soon.