Gauntlet Legends Glitchy Screen Major Issue. Never seen Issue Reported so far.

Flip the switch to go to standard resolution and hook up one of your other monitors temporarily to it and see if it still acts up.
Gonna see if I can find a cheap one on fb marketplace soon. Video cable is really short so gonna have to look into a new one, and how to get this one mounted to the board off safely.
 
Gonna see if I can find a cheap one on fb marketplace soon. Video cable is really short so gonna have to look into a new one, and how to get this one mounted to the board off safely.
I'm not sure what you mean about getting the one mounted to the board off safely. You should be able to just throw a dip switch to go to standard resolution and take one of your spare monitors (I think you said you had spare monitors), leave it on the floor, and run a long video cable to the monitor on your floor.

If you don't have issues there, that means your boards are good and it's just a monitor issue.

This is a divide and conquer problem; it's either an issue with your boards or your monitor, and given that you're running another video card now, it's likely a monitor issue. If so, you can pull the monitor chassis and send it off to be rebuilt and that would likely make you 100%.
 
I'm not sure what you mean about getting the one mounted to the board off safely.
Still got morning brain. I was thinking about the vga cable attached to the main cpu board and not thinking about just hooking up to the video card lol. I had another monitor but recently got broken by my kids (my luck).
Thinking about just hitting up @paul400 Like some have suggested if he'd have time to look at my chassis. Also @demogo , how the hell would I get this entire thing out of the back of my cabinet? There is barely enough room to look at the neck board let alone dropping it down and through.
 
Still got morning brain. I was thinking about the vga cable attached to the main cpu board and not thinking about just hooking up to the video card lol. I had another monitor but recently got broken by my kids (my luck).
Thinking about just hitting up @paul400 Like some have suggested if he'd have time to look at my chassis. Also @demogo , how the hell would I get this entire thing out of the back of my cabinet? There is barely enough room to look at the neck board let alone dropping it down and through.
The monitor comes out the front. And it's heavy. The veterans here will laugh at me for suggesting this, but I'd suggest a second person to help lift it safely out of the cabinet unless you're a really big, strong person. You don't want to bang it around and neck the tube or you'll really be in trouble.

I'm pretty sure that I'm not using a VGA cable in mine but I'm too lazy to move cabinets around and get to the back of mine to investigate further.

If you do have a spare monitor, I'd absolutely suggest that you test with it and a long video cable because you don't have to remove the monitor to do that. Taking that monitor in/out is a chore.
 
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OK, I'm not crazy. The K7500 has a standard video cable hookup on the side and that's what I used when I had a K7500 in my game.


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Over the last week or so I've been doing a lot of tinkering to see what exactly the culprit might be. Got to adjusting the colors on the back thinking it still had to do with the pots, same issue at first, then I started adjusting the contrast/brightness on the daughter board, and BOOM. I think I know where the issue lies at least. Once I started working the contrast back and forth I noticed it got easier to turn and the lines went away! The pot looks fine to me but I am still learning. Was about to get this all ready to pack up and send to paul400 for a chassis repair but I think for now I might be able to nail this demon to the wall. After a lot of color tweaking (which is torture if your colorblind btw), I got it all to a really good level. I know if I adjusted it further from here I could get probably a perfect picture but for now I'll take my win. If you turn the contrast too high, that's when the lines start to come back and appear, at least from my testing so far. So could we chalk this up to a bad pot on the daughter board or should I keep searching further?
 
I might not be as experienced as I'd like, but I'm almost positive it is something to do with the daughter board. I can get rid of the green lines consistently if they pop up, and they only get fixed by fiddling with the contrast and brightness pot. I know it still has an issue, but I'm just happy Im relatively sure I found the problem and how to temporarily fix it.
 
BTW, there are monitor adjustment/calibration techniques printed in some of the monitor manuals that take you through from the beginning. I think some WG monitor manuals have them and they're very helpful.
 
Just got context, if these vertical green lines on the right side in the first 2 pics popup, I can get rid of them everytime now. Then it ends up good as new like in the 3rd and 4th pics. Looks like it's time to brush up on my soldering skills lol.
 

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BTW, there are monitor adjustment/calibration techniques printed in some of the monitor manuals that take you through from the beginning. I think some WG monitor manuals have them and they're very helpful.
100%. I found the WG k7500 manual and it had a lot of helpful bits in it. The parts I could understand at least lol.
 
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So as mentioned, I can get rid of the lines most of the time by fiddling with the contrast and brightness pots, and I've noticed it happens more when the monitor has warmed up for 5-10 minutes. By this point my guess is it's either a control board, or a green circuit issue (possibly the transistor/resistor on the green circuit on the neck board). Does anyone have a good control board guide for a K7500 monitor, or just general maintenance for control boards? I would like to do some basic testing on mine before I have to send it off to the experts.
 
I have the service manual for the K7500 but I am not seeing what they should each measure at.
 

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For reference, the contrast pot in the 2nd pic is right under the "P718-001" on the back of the board.
 

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