CRT Newbie - Where did all the RED go?

[asantora]

Jtb, after some troubleshooting we determined that the red color gun for my monitor tube was shot. There is an opportunity to blast it with a rejuvenator, however, it doesn't appear to be a long term solution.

Before I go on, I want to say that this isn't necessarily the same issue that you're having. If I were you, I would first check your video cable wire from the jamma harness to the monitor to make sure that it has continuity. I also learned to check and flood the transistor for each of the 3 (rgb) transistors. After I did not see much red, I was told / learned that my tube was caput.

So, my solution was to buy an old tv and rbg to tv converter and wire that up (still a work in progress).

Hope this helps


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[asantora]

By the way, this is what my tv looks like - it's suitable for me


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[jtb1987]

asantora,
Thank you for the reply - would you mind going even further in elaborating on the options you gave to troubleshoot further?

I also just realized that if I hold the grey cord differently that goes from the jamma to the monitor, I can get the color to work correctly....does this indicate that there is something wrong with the grey cord, the jamma connection, or the neckboard connection? When i hokd the grey cord straight up, it seems to fix the color. If it bends slightly at the monitor connection, the color goes to all blue. What would I need to do to holistically solve the this issue? Would just replacing the grey cord fix it and if so what is it called and where do you buy them?

See images of grey cord and how I got red to come back by holding it differently...

[buttersoft]

Simple problem then, after all

"The Jamma to the Monitor" meaning the Jamma edge of the Tekken PCB to the first part of the Chassis (PCB that drives the monitor)? (The chassis is the big board, the neckboard being the little PCB attached to the pointy back end of the CRT itself, farthest from the flat side where the picture shows.)

Check the solder joints under and around the connectors of that grey cable at both ends. Even if they look ok you could reflow them. If it's not that, see if you can get a needle or pin into the ends of the connectors, to narrow the holes, so to speak, and help them hit the pins. If they still won't grip, you might have to redo the cable.

EDIT: looking at the pics more closely, there's a bit of room there to wiggle those wire individually, or at least watch what pulls on what when you move the cable.

[asantora]

 That grey cord provides your video signal from your jamma harness / game board to your monitors circuit board. I'm still learning here but the way I would approach this is to disconnect the grey connector from your monitors circuit board. With it disconnected from the circuit board to the monitor, I would then put a multimeter on one end of the missing color's jamma harness side wire and the other one on the molex connector side and test for continuity. I would move the wire around as your testing to see if the connection breaks. If it does, I would simply run new wires to the monitor from the harness.


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[lilshawn]

it's pretty common for the solder on the board to be cracked at that connector. it's a really tight fit and often you have to really pry/crank on the connector to get it on or off.

if you look at the backside i'll bet you can see it.

[jtb1987]

Thanks everyone for the replies!

Thankfully it sounds like a correctable problem.

First off, what is the name of the grey cord? Is there an online parts shop where I could buy a new one?

With that said, it sounds like cord isn't really the problem - it's the connectivity between the cord and the connection to the monitor chassis. I apologize but I'm still a little bit confused on how I would go about fixing it...do I need to re-solder the connection? I wouldn't solder the cord to the board as its meant to disconnect so I'm just unclear exactly the next steps...

Thanks everyone for being so helpful.

[pbj]

Discharge the monitor.

Take out the board.

Reheat the solder on the board where the grey cable plugs in.

[astroroxy]

So I have been looking all over, but does anyone know what monitor this actually is?
This is the first one that I have been able to see exactly what it is.

[lilshawn]

are you lost? there are literally thousands of pictures of the WG K7400 / K7500 monitor chassis out there. I find it hard to believe this is the first picture you've seen of it.

[astroroxy]

are you lost? there are literally thousands of pictures of the WG K7400 / K7500 monitor chassis out there. I find it hard to believe this is the first picture you've seen of it.

So this is actually a sharp image.
From what I can tell it's a close clone to the K7100, definitely not 7400/7500
(I'm talking about the pics from the original poster.)

[lilshawn]

oh you mean way way back in the beforefor times, not the last pics posted. (http://forum.arcadecontrols.com/index.php/topic,152601.msg1602437.html#msg1602437)

 

[astroroxy]

oh you mean way way back in the beforefor times, not the last pics posted. (http://forum.arcadecontrols.com/index.php/topic,152601.msg1602437.html#msg1602437)

Yep, the original pics

[lilshawn]

but yea, the original pic was a sharp image k7000 clone

http://www.homearcade.org/BBBB/monitor78.html