Can you test the video output of a Jamma cabinet with a multi meter to see

[TheRCGuy]

Can you test a Jamma video signal with a multimeter with a multimeter? And not have to buy a monitor to see if the jamma boards are good.

[ChadTower]

There's no way to know if the video signal is what it's supposed to be, just that it falls within the proper range.  The video signals are constantly moving up and down in voltage within a specific range.  You could verify that there ARE video signals, but there's no way to know if they're corrupt (e.g. bad rom, too weak, too strong, etc).

[Ken Layton]

The video signal can be as high as 5 volts. Generally though only a multimeter will tell you that there is a voltage coming out of the jamma board. It can't tell you about the quality of the signal.

[Thenasty]

Can you test a Jamma video signal with a multimeter with a multimeter? And not have to buy a monitor to see if the jamma boards are good.

You can play the gmae blind and hear the sounds, then you know the PCB is good.

[ChadTower]

No you don't, you still don't know that the video signal is good that way.

[TheRCGuy]

I purchased a used Nanao 19" (MC-1830-s) monitor and hooked it up with worked good for about 1hr then the monitor went blank. When you power it on you do not hear the high voltage crackling in the monitor. Any Clues what to check? The game still opperates the same why it did before I hooked up the monitor.

[Ken Layton]

Nanao monitors operate on 100 volts AC power (Japan standard). In Sega cabinets and Nintendo cabinets they had stepdown isolation transformers that dropped the 120 volts AC (USA standard) down to 100 volts AC to prperly operate these monitors. If you put this in a game that supplies 120 volts to the monitor or you did not use an isolation transformer then you just cooked the power supply section of your monitor and maybe took out the horizontal output transistor too.

[TheRCGuy]

Is there any way to repair this? Or is it just junk now?

Thanks for your info!

[ChadTower]

Yes, you repair the sections that Ken just mentioned.

[TheRCGuy]

Can you refer me to a place where I can get parts for this? Also how can I reduce the 120v down to 100v without buying a stepdown transformer?

Thanks again for the info!

[Thenasty]

Can you refer me to a place where I can get parts for this? Also how can I reduce the 120v down to 100v without buying a stepdown transformer?

Thanks again for the info!

I have one from my Nintendo Cabinet. You interested LMK.

[ChadTower]

Can you refer me to a place where I can get parts for this? Also how can I reduce the 120v down to 100v without buying a stepdown transformer?

Thanks again for the info!

That's what a stepdown transformer DOES, though you could probably stand there and hold the live wire to reduce the voltage some.

[TheRCGuy]

MAN!!!! My finger is burnt to a crisp!!!! I tried holding the live wire to reduce the voltage and it did alright at first until my finger started smoking!!!!   

[Ken Layton]

Some of the game parts distributors sell an isolation transformer with multiple output voltage taps. I worked on an old Leland Off Road a few weeks ago and noticed it came from the factory with a tapped isolation transformer. Quite unusual for an old game.