Multicade Help

Now in that last picture I posted, do I need to be more concerned with the black box on the left, which I believe is the power supply we are all talking about or should I also be concerned with the white/silver smaller thing to the right of it? And what exactly is that part if anyone knows?

Again, I am not familiar with any electrical at all and dont have a multimeter. That is why I wonder if it is best just to spend the $25 on a new power supply and not worry about buying a multimeter. And if for some reason I don't need the power supply I just put it up on ebay and make my money back on it.
 
You can replace the power supply no problem.

The smaller white/silver thing on the right is called a transformer. An isolation transformer, to be more exact. That isolation transformer provides power to your monitor. Does your monitor make any noise at all when you plug in/turn on the game? You should at least hear the crackle/static sound of the degauss circuit when the monitor turns on. Put your hand on the front of the tube (if you can get the front bezel glass off easily) - if you feel static, then you're monitor is turning on correctly.

If you have no monitor raster AND no lights on the multiboard, then you have 1 of 2 issues to address:

1. Your cabinet's AC line fuse has blown. This fuse is normally located on the floor of the cabinet, close to where the wall cord comes into the cab. Pull the fuse out and don't just LOOK at it, TEST it with a meter to make sure it's good.

2. If the AC line fuse is OK, then you have a power supply that has failed AND you most likely have a monitor that's in need of repair.

To replace the switching power supply, you'll see that there are 7 positions on the one in your game, 6 of which are used. Simply unscrew all 6 connections and hook everything up to the new power supply in the same way. No need to employ any special tools or grounds or anything. Just make sure the game is unplugged while working on it.

If you replace the power supply and the game starts up, makes noises and plays but there's no image showing on the screen, then you have what's called a game that's "playing blind." That means your monitor has failed and you need to get it repaired.

Yes, you are correct, the marquee light WOULD come on even if the game's power supply is hosed. They get their AC feed directly from the incoming line cord.

Hopefully this information helps....
 
kmtgod said:
Again, I am not familiar with any electrical at all and dont have a multimeter. That is why I wonder if it is best just to spend the $25 on a new power supply and not worry about buying a multimeter. And if for some reason I don't need the power supply I just put it up on ebay and make my money back on it.
Click to expand...

Get a $10 meter from Harbor Freight or similar. You don't need anything fancy.

These game power supplies are adjustable. When you install a new one, you need to adjust it for the correct voltage so you don't fry the board. You can't do that without a meter.

Generally speaking, it *should* just work - but if that adjustment knob got tweaked somehow, or if the supply was previously adjusted for a board that drew a lot more current, then it will be out of whack. I always double check the voltage on the supply before I hook it up to a board.

General procedure:

Install the power supply, connecting it up to the harness.
Unplug the JAMMA connector from the game board.
Power on the game, and adjust for 5v at the supply.
Shut the game off, plug the board back in, fire it back up.
Readjust the 5v (it'll change now that the supply has load on it).


You wouldn't own a car without owning a tire pressure gauge, and you shouldn't own a game without owning a meter. It's an inexpensive and vastly amazingly useful tool.

-Ian
 
cadillacman said:
ok lets test basics here..


do you have a digital multimeter?( volt meter) or know someone who does?

If not, go buy one. A cheapie can be had at harbor frieght for like $10.


with the game on check for 120vac at the "ac" terminals on the power supply

next, set the meter to dc volts....

stick the black lead on the "gnd" terminal, and the red on the +5 terminal. WHat is your reading?
next stick black on gnd, and red on the +12. what is your reading?

ALso, at the power cord going to the monitor, backprope it with the meter, check to see if you have 120vac going to it.


no flashing leds on the multiboard make me suspect a board issue or power supply issue, but id expect a flash or dot or something on the monitor
Click to expand...

+1 on the meter...You need this to check the fuses also and not just by looking at them.

Read this thread also and you can see how a meter can be an asset.

http://forums.arcade-museum.com/showthread.php?t=197101
 
Last edited:
My experience tells me it's a bad PS or bad game board. Don't just go and buy a new PS without testing the old one first. You still need to adj the new PS or you will blow up your board if it's set wrong.....buy a VM and test the thing already or call someone who can fix the game for you.

Having arcade or pinball game you will have to eventually do some kind of work or have someone close by who can fix them for you.
 
By the way... If you are testing the fuses with the multimeter on continuity or resistance measurements... THE GAME MUST BE UNPLUGGED.

Do not measure current or "A" with the meter. Do not use that setting until you know more about how to use your meter.

If you are testing voltages (AC and/or DC) then the game MUST be plugged in. You may need to test it with the power off or with the power on depending on what you are trying to test. Take off any rings, watches, etc. before you do these kinds of tests for safety reasons.

If you ever notice, electricians don't wear jewlery. If they are missing a ring finger then they learned it the hard way.
 
Thanks for all the help. I really appreciate it. Per what rhombus mentioned, does anyone know of anyone in the Milwaukee, WI area that works on and fixes arcade games. If the fee was small enough, I think I would feel more comfortable someone correcting this issue for me. IF not, then I guess I will go with the multimeter and test things out and follow everyone's instructions. Thanks all.
 
Ok, got both a multimeter and a new power supply since they were both fairly cheap. Figured I could resell the power supply if that is not the issue and make my money back.

So, I am still getting nothing on the screen at all, Marquee lights up as well as the coin doors and there is a loud buzz noise to it.

The readings I am getting with the multimeter are:
119.5 on the AC- so I believe that is all ok and shouldnt be the issue.

For the +5 I am getting .12
and the +12 I am getting 4.32

So maybe the board is the problem and what would need to be replaced? Does that sound about right if it was, would it cause these issues? Thanks again all for the help, jumping into this somewhat blind.
 
For your +5 and +12 voltage measurements, are you making sure your meters is set to measure DC voltage, not AC?

119.5 sounds right for the AC measurement, but if your meter is not auto-ranging or auto AC/DC, you need to make sure you're testing for the proper type of voltage.
 
Then one of two things is happening: either the power supply you got is no good (possible), or the something is wrong with the board, causing a power drain.

Can you test the power supply without load and see if your values change?

We need to get a known working power supply tested before we can confirm whether or not you have board trouble.
 
ok, the +5 was the same, but the +12 went up to about 6.72 with everything disconnected but the AC. Buzz noise still there.
 
Ok, so I reconnected my old power supply which I thought was the initial problem. The AC measurements are coming just under 120 so that is fine.

But for +5 and +12 I am getting a 0 reading and there isnt that loud buzzing noise?

So, do you think my old Power Supply is completely shot and this new one off of Ebay just is crap? Thanks again for this guidance.
 
No, I just bought this new at Sears. I had tested out a couple other things around the house and they all came up at measurements that they should have. So maybe it is power supply?
 
Did you test it with anything else DC? Do you have a 9v battery laying around?

Otherwise you can test a laptop power adapter with it - that should also output DC voltage.

As long as you've confirmed that your meter is good, then you can pretty much assume that the new power supply is no good if it does not show correct voltage on the +5 and +12 lines. Especially the +12 line. That should be pretty close. The +5 is adjustable and could be off based on the pot being turned one way or the other, but the +12 should be close.
 
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