Help - No picture in Cabinet - unknown wire disconnected

Cliff Clavin

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Help - No picture in Cabinet - unknown wire disconnected

Hi people,

I am trying to get a jamma cabinet up and running with mame...The eventual plan is to put jrok's board into it but first I am trying to get it running....The cabinet worked before it went into storage but now after several years, I am not getting an image at all...I believe the monitor is getting power because it makes that quiet sound when I disconnect power from the cabinet....the sound is hard to describe but it common to all crt...

Enclosed is a picture of a wire that had one end hanging loose in the cabinet and whose purpose is unknown to me....I suspect it may be some kind of ground but I am hoping one of the more seasoned members can help me identify it...The way the wire is soldered in leads me to believe its was added by one of the cabinets previous owners as it likely did not come this way from the factory.

The wire in question is the one that is nearest the flashlight....One end of the unknown wire is soldered into the middle of another wire which runs the around the back of the monitor....The unknown wire has a connector on the end of it but I do not see where it could plug in...

Could this unknown wire be a secondary ground wire causing my lack of image whatsover? I disconnected the jpac to see if I got any image (making the assumption that the neo geo cabinet would have some image even without a cartridge) but alas, no luck....

I would be very grateful for any advice...

thanks very much.

C.
 

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from what you say that it is.

it probably is your dag wire.

Peace
Buffett

You are correct Buffett.....I searched for Dag wire and came up with this image from another thread.....

Can I then assume its ok for the wire to remain unconnected and that my lack of image problem lies somewhere else??

Thanks
 

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It should be connected, but it's not your issue.

Get a multimeter on that switching power supply and verify you have +5 coming out of it....
 
NO!!

it must be connected or you will damage the chassis.
connect it to the neck board before you turn the game on again.

Peace
Buffett
 
NO!!

it must be connected or you will damage the chassis.
connect it to the neck board before you turn the game on again.

Peace
Buffett

Seriously? Here is a picture of the connector, I don't think it was attached to the neck board (board right below the end of the tube)
 

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Yes it was. You'll find a small flat stand-off on the neckboad that this connector will slide on to. Over time they get loose and slip off.
 
Yes it was. You'll find a small flat stand-off on the neckboad that this connector will slide on to. Over time they get loose and slip off.

You are correct sir!....I put on my rubber gloves (I hate messing around with monitors) and plugged it back in...took a bit of time finding the spot but hopefully there is only one empty spade on the neck board....

however, still no picture....arggghhh....I didn't smell burning or hear any crackle but could I have damaged the monitor? Its a 25" RCA in a jamma cabinet...

Any other ideas on the no picture?

Does a neo geo jamma cab show any picture when no cartridge is plugged in???


Thanks

C.

Edit: I just noticed that the sync ok light on the jpac is not lit....I am wondering if the problem is with the jpac?
 
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yes it is probably damaged.
almost all monitors will smoke parts if that wire is not connected.

what chassis is on your tube.

yes you should get a grid pattern and the setup screens with no cart in the system.

Peace
Buffett
 
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yes it is probably damaged.
almost all monitors will smoke parts if that wire is not connected.

what chassis is on your tube.

yes you should get a grid pattern and the setup screens with no cart in the system.

Peace
Buffett

ARRRRGGGGHHHHHH.....oh crap.... I am pretty bummed out here....I am at work so I can't check the chassis out until I get back home....I will take a picture of it and hope someone can identify....

Thanks guys....

bummed in canada....
 
yes it is probably damaged.
almost all monitors will smoke parts if that wire is not connected.

what chassis is on your tube.

yes you should get a grid pattern and the setup screens with no cart in the system.

Peace
Buffett

Could it be a hantarex? Here is an image.....
 

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The mystery deepens....I found another set of wires coming from the power supply...it has two ends on it...there is a piece of paper with my writing on it that says top.....

I am pretty sure it goes to the switching power supply...its the 110 going to it....

any reason why i shouldn't connect them up? Does it matter which wire goes to the 115 on the switcher??
 

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I was really hoping those two wires were the cause of my problem but after connecting them to the power supply, still nothing.....Drat....

anyone know what the switching power supply is for? It looks like it provides power to the jamma connection....

given that there was no power previously going to it, I was hoping it would have protected the monitor from the missing dag wire...does not look likely now....
 
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You said in 1 post those wires were coming from the power supply. Then in your next post you said you connected them to the power supply? I'm a little confused.. BTW just so you know your metal braid around the tube is your ground. lol
 
Well to give an update in case any is still following the thread....

I was able to connect with a fellow collecting friend who made a service call and with his help (and spare board) the cabinet is now working....

As near as we can tell, my mame computer box is not working properly.....I think the jpac is fine but it appears that the computer is not booting into mame properly....

The monitor now works and fortunately nothing was fried from powering on the machine with the now identified dag wire disconnected....lesson 1 for me....

This neo geo cab does not display an image when there is no cartridge connected...in fact, the screen stays completely blank...leading one to believe there is a monitor issue....lesson 2 for me.....

So to sum up, buddy fidled with the chassis, connected the new jamma board and adjusted the monitor and voila...picture and sound...the cabinet is back in action and ready to play robotron again....

I did realize that the 5,6 buttons do not seem to be connected on the cabinet so I am pretty sure I read instructions here for doing that, so I am off to search for it.....unless someone has a link they feel like sharing...

Regards to all and thanks for all the help....

Last question for someone: Does Jrok's board need any additional wiring to use buttons five and six? I have an older 19 in 1 currently in the cabinet and the buttons 5 and 6 are not registering....I see where later versions of the 19 in 1 can use these buttons....Not sure where Jroks board fits in to all of this....If it needs any further wiring to use 5 and 6....I guess it can be called a kick harness....
 
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As an add on - the 4900 will not fry if the dag wire is not connected. In fact, the only monitor that I know for sure that will fry from an unconnected dag wire is the K7000/K7200 series....
 
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