Process for testing monitors, without a cab?

[Sarver Systems]

I normally bring monitors home with me to recap and perform repairs.

The problem is, I have no way to test them until I take them back and connect them back to the cab.

I know I need an isolation transformer, but what do you guys do to test the monitors?

[Generic Eric]

Hit up Nephasth.  I think his build fits your need.

http://forum.arcadecontrols.com/index.php/topic,121731.0.html

Here's my next little project. I'll be building a portable JAMMA test rig/supergun. It will be able to test JAMMA game boards by itself thanks to a 7" monitor. It will also be able to test arcade monitors with its RGB-S video out and isolated power out. It will have composite, s-video, and VGA out and internal and external audio. Also 2 DB15 connectors for NeoGeo and custom controllers. Just got the case the other day, and will be ordering the rest of the parts soon.







Want one? I'm thinking about building more than one: http://forums.arcade-museum.com/showthread.php?t=244322

[Sarver Systems]

I was hoping for something cheaper, and easier. I don't need to test the jamma boards or anything. Not yet anyways.

Oh hell, I should just bite the bullet and build a supergun. I'm going to need it sooner or later anyways!

[mgb]

I use a cheap jamma board and powersupply. Its pretty cheap to build. you can pick up an unpopular jamma board for cheap and get a cheap switching power supply and harness as well as an isolation transformer.
I have a RoboCop jamma board that I use for this work. Its a fairly small board so its easy to bring anywhere as needed.
I keep the power supply and iso transformer, along with the jamma harness, tucked away in a little portable tool box. you may also wanna consider that different monitor power inputs and video plugs may differ.
for testing, I usually just have the pins bare from the iso (crimped but not in plastic amp connector) and i just push them in and tape.
you can also make up some nicer quick connects for this.

[Generic Eric]

I was hoping for something cheaper, and easier. I don't need to test the jamma boards or anything. Not yet anyways.

Oh hell, I should just bite the bullet and build a supergun. I'm going to need it sooner or later anyways!

Word

I suggested it because I recalled that it was used for testing monitors. 

[Ken Layton]

I normally bring monitors home with me to recap and perform repairs.

The problem is, I have no way to test them until I take them back and connect them back to the cab.

I know I need an isolation transformer, but what do you guys do to test the monitors?

For most monitors in general, only two items are needed:

Isolation transformer.

Monitor pattern generator. It plugs in to the signal input of the monitor and gives you pictures you can use to adjust brightness, contrast, centering, horizontal hold, vertical hold, and convergence/purity.

"CraftyMech" over at the KLOV forums is just now releasing an absolutely wonderful (and very reasonably priced) monitor pattern generator designed specifically for arcade monitors:

http://forums.arcade-museum.com/showthread.php?t=297247

It even does positive and negative sync plus has a color inverter for Nintendo monitors. There is also a CGA/EGA selector and a burn-in mode. Strongly suggest you BUY it! He starts shipping them on May 5th.

If you plan on doing Nintendo monitors or others that require operating voltages of 100 volts, get a "VARIAC" (trade name for a variable power transformer). You plug the isolation transformer into the output socket of the Variac. Then you can turn the knob on the Variac down to 100 volts. This gives you isolated 100 volts. A Variac is NOT an isolation transformer. It merely drops the voltage.

I got my isolation transformer out of an old video arcade game we parted out. It even had the correct connector on it's output cable to plug right into Electrohome monitors.

[Sarver Systems]

Funny you should mention to Nintendo monitors. I do a lot of those, and a lot from Ms. PacMan/Galaga. G07? The name escapes me at the moment. Something EZ. Eh, whatever it is.

[mgb]

The Sanyo 20ez

[Sarver Systems]

Yeah, that one. I do a lot of G07's too.

[twistedsymphony]

...
"CraftyMech" over at the KLOV forums is just now releasing an absolutely wonderful (and very reasonably priced) monitor pattern generator designed specifically for arcade monitors:

http://forums.arcade-museum.com/showthread.php?t=297247

It even does positive and negative sync plus has a color inverter for Nintendo monitors. There is also a CGA/EGA selector and a burn-in mode. Strongly suggest you BUY it! He starts shipping them on May 5th.
...

I got my isolation transformer out of an old video arcade game we parted out. It even had the correct connector on it's output cable to plug right into Electrohome monitors.

WOW thanks for that link, I've added my name to the list of people who want one 

Not to stop on the Ops toes but I had a couple of questions about ISO selection...

1. Will any ISO work with any monitor? or will I need different ISOs depend on which monitor I'm using.

2. Is there any harm in using an ISO on a monitor that doesn't need one? I ask because most of my machines have newer monitors without the need for an ISO, but it'd be nice to just always hook them them up the same way when testing.

[Ken Layton]

1. Yes, just about any isolation transformer will work with any monitor. Arcadeshop sells a nice one for $19:

http://www.arcadeshop.com/parts.htm#Monitors

2. There is no harm in using an isolation transformer with a monitor that doesn't need one. If you do repair work on monitors that don't need isolation, be advised that everything on the input side of the monitor's built-in isolating transformer (part of it's switching regulator design) is still "hot chassis" and you'd need to use an isolation transformer when testing that portion of the circuit lest you blow up your test equipment.

[twistedsymphony]

awesome info, thanks 

[rCadeGaming]

I was also going to suggest a test pattern generator. 

Another suggestion for a very cheap solution would be a GroovyMAME PC or an old game console wired for RGB, with a circuit to step up the signal levels to what an arcade monitor is expecting.  You could get 240p, 480i, 480p, and some test patterns from a Dreamcast.  There are monitor test programs available that just need to be burned to a disc.

http://junkerhq.net/xrgb/index.php/240p_test_suite

[Sarver Systems]

Do you think this work as a small inexpensive LCD for this?

http://www.ebay.com/itm/7-inch-TFT-Car-LCD-Display-Module-w-VGA-Video-AV-Board-Optional-Touch-Panel-/291020349128?pt=LH_DefaultDomain_0&hash=item43c22a1ec8

[Ken Layton]

Inexpensive pattern generator called the "TPG" is now shipping.