So, you finally picked up an arcade machine and you are trying to figure out what to do first.  Let me take you through some of the things you should check and some of the options that you have.



Before I even plug the machine in, I look at the plug.  It is is damaged, or just doesn't look right, I replace it.  In this case I'm using a plug that will allow me to push the machine as close to the wall as possible.


Before I start messing around with the monitor and board, I like to check the power supply, especially if you bought a non-working game.  Many times, you just need a $30 power supply and you are all set.

This should go without saying but WHEN WORKING WITH LIVE WIRES, BE VERY CAREFUL!  THERE ARE A LOT OF WAYS TO GET SHOCKED INSIDE AN ARCADE MACHINE.

Your power supply should look something like the image below.  There will be terminals for +5v and +12v.  Plug the power cable into the wall and check these terminals with a multimeter set to DC Volts to make sure the voltages are correct.  You want them to be slightly higher than their designated value since they will encounter a little resistance on their way to the board.  If they are a little off, use the knob on the power supply to allow more or less voltage through.  If you either get no voltage readings or if they are VERY low (with the power cable plugged into the wall) you have a bad power supply.  Buy a new one and swap it out.


Once your power supply voltages are correct, it's a good idea to check the B+ voltage on your monitor.  There is a great article on some of the finer details of arcade monitors on KLOV, but if you don't want to read all of that, just know that B+ is the high voltage power for your monitor.  On some monitors, it can be adjusted with a knob just like on your power supply and on others it cannot.  For example, B+ is adjustable on the Sharp monitors in my PlayChoice 10 but NOT adjustable on the Wells Gardner K7191 in the Tekken Tag cabinet I just picked up.  The test points will vary by monitor so do some googling to find the procedure for you monitor.  For my Wells Gardner, I am looking for 130 volts DC on the near post of this large white resistor on the side of my monitor chassis, and I got 130 volts.

While we're looking at the monitor, let's make sure the flyback transformer isn't in need of replacement. 

DANGER!  The flyback transformer has a large red wire connected to a suction cup on the monitor tube, this is the voltage that can kill you.  DO NOT TOUCH THE RED WIRE, FLYBACK, SUCTION, CUP, OR THE WIRE UNDER THE SUCTION CUP WITHOUT DISCHARGING THE MONITOR FIRST.

Even if your monitor works, check the flyback.  If the flyback goes, it will allow all sorts of crazy voltage into places that crazy voltage wasn't meant to go and it will cost you a LOT more money in the log run than just replacing a flyback that is on it's way out.  How do you tell if a flyback is on it's way out?  It will be cracked or oozing clear fluid.


Well, crap.  I've got a cracked flyback transformer.  Not great news, but it could be worse.  Now that I know the flyback is on its way out, I will not be turning the monitor back up until it's replaced.  And since I have to remove the chassis (the monitor's main PCB) to replace the flyback, I should consider a cap kit.


The most common monitor repair/maintenance job is called a cap kit.  "Cap" referring to all of the capacitors on a monitor chassis.  The dielectric in capacitors dries out over time and they lose their ability to, well, be capacitors.  Since most of these monitors are pushing 40, it's usually a good idea to replace the caps with new ones whenever you pick up a new monitor.  All you need is a soldering iron, a desoldering pump and a cap kit for your specific monitor.

Once all of the safety checks and monitor maintenance is complete, it's time to play some games!  You have several choices depending on what kind of cabinet you picked up.  If you picked up a JAMMA cabinet, you can swap other games in and out of of with no additional adjustments as long as the game doesn't have more then 3 buttons.  The JAMMA standard only officially supported 3 buttons (sometimes 4), so if your game has more than 3, you will need to wire the additional buttons to the kick harness for your game.

My control panel has 5 buttons per player.  I would really like 6 buttons per player for Capcom fighters and MK games and ideally 7 buttons per player with a hybrid Street Fighter Neo Geo layout, so I will need to do some drilling...Or will I...


The control panel already has holes drilled for a capcom style control panel!  All I need to do is order a couple of push-buttons with microswitches, wire those bad boys up to my shiny new J-Pac, and I'm off to the races!

What's a J-Pac?

If you want to connect a PC to your JAMMA cabinet for a little MAME or other emulator action, there is a board made by Ultimarc called the J-Pac.  This board will allow you to connect your JAMMA wired cabinet to your PC.  This will be my next step after re-capping my monitor and replacing the flyback.  I'll be writing up an article on that procedure next month.

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