Wells Gardner 25k7401 Color issues in corners

[techn0]

I have a Wells Gardner 25k7401 in my Area 51 Site 4. I was about to sell it until I tried it. The screen had gotten darker over the years. It has been turned on for 10+ years straight. Well I went to play it before having the buyer pick it up and the guns did not track on the screen. I adjusted the brightness the best I could and they started working in the center of the screen where it was the brightest and clearest but that was the best I could do. So I did a cap kit. Not much change. Checked R811 and it is good. Replaced the flyback. Colors seemed better but still not good enough for guns to work as they should apparently.

When I do screen tests in test mode you can really see the corner color issue I am having. Also white is not very white. If I turn the screen up much more with the flyback adjustment the screen becomes impossible to focus.

Here are some pictures of the different colored screens. I would love any help you all could provide.

 

[paul400]

is the yoke loose? check the yoke rings as well.

 

[bman7418]

Did you try a degauss

 

[techn0]

I will inspect yokes after work today but I was under the understanding that the yokes pulls the beam up/down and left/right which is happening.

This monitor has a built in degaussing coil so I figured that was not the issue?

 

[JakeJones07]

I agree with Paul. I'm guessing your yoke got bumped. You might loosen the yoke and see if pushing it closer or further from the tube helps. Depending on how much adjustment you do. You likely need to adjust focus rings slightly.

 

[techn0]

Played with yoke tonight and did some research. I am able to twist the whole assembly which literally rotates the picture. Not the cause. I was able to slide the yoke assembly in tighter and that drastically improved the colors.

I was able to play through the game with gun two and beat it on the first try so I am happy with that gun but the player one gun still only works on very center of screen. I am going to order the pcb for the gun to see if it corrects the problem. I have already cleaned it and swapped inputs on the game board to no improvement.

Thanks for the yoke clue.

 

[mecha]

I've seen multiple K7400s over the years where the yokes were just set wrong from the factory. loosening the set bolt and smashing it up against the tube as much as possible fixed it for me, though that technically shouldn't be the solution, it worked.