How to power monitor with no PCB

[crapjoint]

I was told if you hook up a PC with Mame and therfore disconnect the PCB that you have to do something to the power supply because it can't be running without a load.  How do you power the original arcade monitor by itself?

[OSCAR]

The arcade monitor is not powered through the power supply.  The power supply is there to supply +5V, +12V, and -5VDC (in the case of switching jamma power supplies) to the game pcb and sometimes the coindoor lights.

The arcade monitor is typically connected to the 110VAC coming into the cabinet through an isolation transformer.  Newer arcade monitors don't require isolation transformers, but verify if yours requires it or not before eliminating it.

[menace]

The last three dedicated cabs that I have received had the isolation transformer first in line with its output going to the input of the power supply--from there to the +5, +12, monitor etc.  Anyone else see this arrangement?

[OSCAR]

The last three dedicated cabs that I have received had the isolation transformer first in line with its output going to the input of the power supply--from there to the +5, +12, monitor etc.  Anyone else see this arrangement?

No, I've never seen a monitor powered from a jamma supply, nor have a seen a jamma power supply with AC outputs.  I've seen them wired in parallel, though.  See the cabinet wiring schematic here:

http://www.dameon.net/BBBB/buildit.html

[crapjoint]

My game only has one power supply, it is a Jamma cabinet.  The power wires for the monitor come right out of the power supply.  How can I power the monitor without the gameboard but not ruin the power supply?

[OSCAR]

Any chance you can take a photo of how your monitor power wires are connected?  Are you sure that the monitor power isn't just wired in parallel with the AC input to the power supply?

Out of all the power supplies that Happ sells, I only see one that has an AC output, and that is an 1.0A line for bill validators.

[crapjoint]

If it is in parallel, it would be inside the power supply case.  Does this mean, you have to open it and disconnect the part that goes to the board?  I'll open it up later and take some pics.

[OSCAR]

Yes, post some pics of what you have and how it is connected, and we'll get you running.  

[crapjoint]

My camera is still broken but I opened up the power supply and this is what I see.  There is one wire(casing with 3 wires inside) coming from monitor, which splits in the middle to power coin doors, and goes into power supply.  Then there are a bunch more from Jamma board going in with the monitor wire.  On top there is also another power cord plugged in like the one that goes into the main outlet for power which goes up to feed the marquee light.  Inside the power supply the monitor wire opens and green goes to ground and white and black go to the switch on the supply.  Also on the switch are 2 other wires which go to the fuse, and the other I can't tell.  Doess this help?

[crapjoint]

Noone knows?  I have a replacement monitor that I bought that had no power supply.  If it was supposed to have a transformer and now I don't have one what will happen if I power it up?  Is there any way to find out what I need to power it, and can someone tell me how?  Monitor is a Hantarex Polo 25"

[menace]

I'll be honest, I had a hard time following your description--if you could even draw it on paper and scan it in, that would help.  I'm no expert but most arcade monitors need the isolation transformer in there, to not have it would damage it.  You'll have to wait to here from ken (no pressure ken  ) on the specifics of a hantarex 25"  --I'm sure a model number would go along way if you've ever managed to track one down--have you checked bob roberts site and did some comparisons?

[crapjoint]

As far as I know, polo is the model.  It says on it model:polo 25".  And on their website, this seems to be the right model number.  Please see pics, I did best i could.

[crapjoint]

One more pic, I have a couple more if needed.

[OSCAR]

Thanks for the pics, that helps a lot.  Based on what you have there, I would find it easier to remove the power supply altogether and run new power wires for the monitor.  Unless you know for a fact that your monitor does not require an isolation transformer, make sure you use one or you could seriously damage the monitor and yourself.

You will also want a power switch for the monitor, too.  Radio Shack or other electronics retailers carry a variety of AC power switches.  The easiest one to use for this will be a SPDT switch, something like this.


If it were my cabinet, I would wire it as shown below.  You could also include a line filter, too.  Bob Roberts carries everything you need to do this, or you could get everything, except possibly the isolation transformer, from someplace like Radio Shack.





 

[crapjoint]

Thanks for the help.  I think you're right and it would be easier to just power it up separate.  I didn't want to mess with the power supply too much anyway.  This brings me to my next question now.  Are all isolation transformers the same?  How do I know what I need for my monitor if not?  So would I just take a regular power cord and cut the end off to do this?  Would you happen to have an actual picture of a real monitor setup like your diagram(just so I make sure I got it right)?  Thanks again for the reply

[OSCAR]

I've seen isolation transformers of various sizes, but they are interchangeable.  It would be difficult to for me to take a photo of an actual setup showing all the individual components as the wires are are all bound together and not easy to identify which one is doing what.  If I can get in behind one of my cabs and snap a few pics, I will, but I'm not sure how much that will help.