Monitor adjustment questions

[Mario]

I've got a lot of questions. Here's a few more.  These all pertain to a 25K7194.

1. The screen size of my display is very wide. I want to shrink the horizontal size. According to the manual, there's a horizontal adjustment on the chassis which is a large white item, but I can't figure out how to actually perform the adjustment. Do I stick an adjustment tool inside the white item and turn it like a POT? I did try this, but nothing seemed to turn, so I wasn't sure if this is how it's supposed to work. (and yes, I only use plastic adjustment tools  )

2. I want to shrink the vertical size of the screen to provide a better fit. I adjusted the V-Size POT, but it doesn't make the screen small enough. Is there another vertical size adjustment somewhere?

3. I don't get enough red color, even after lots of adjustments of the RED DRIVE and RED CUTOFF pots. And if I increase the brightness of the screen, the red color bleeds. Will a cap kit fix this, or will it take something more drastic?

I'm trying to avoid having to do a chassis swap if I can avoid it (see my other thread).

Thanks.

Mario

[Ken Layton]

1. Yes, you stick a plastic television alignment hex tool (of the correct size) into the width coil (a.k.a. horiz size) and turn it like a pot. Be sure you have the correct size tool as there are literally dozens of different ones and they are all METRIC. If the powdered metal 'slug' in the coil does not turn (or is very hard to turn) it's because the factory put a drop of glue in there. Try heating the width coil with a hair dryer to soften the glue. If that doesn't help then you must buy a new width coil (Bob Roberts has them). The replacement width coils do not have any glue applied to them so they turn like they should.

2. V Size, V Lin, V Hold, V pos, and the 50/60 Hz pots all interact with each other. Sometimes it's merely a matter of tweaking them all. See www.jstookey.com/arcade/WG_25k7191/ for more information.

3. Picture tube has weak emission on the red gun. It may be fixed by putting the tube on a rejuvenator machine. If the rejuvenator can't help it then the picture tube is shot and must be placed ($$$).

[Mario]

Once again, thanks for the quick and useful help.

Mario

[Mario]

I turned the horizontal size adjustment pot as suggested, by sticking a hex tool inside the pot and rotating it. However, nothing happened to the picture. The size did not adjust at all. Could I have a bad pot? The size is currently quite a bit larger in width than it should be, cutting off a significant portion of the picture.

Also, what does the horizontal hold do? When I turn it, I see the screen move slightly side to side, just like the horizontal position pot does (only not as much). Is that all it is supposed to do? I'm just curious.

Thanks.

Mario

[Ken Layton]

Did you use the correct size hex tool? If too small or too large you might think you're turning the slug but may not be. It's possible the Wells-Gardner factory may have glued the slug in place. Try heating the coil with a hair dryer to soften the glue. If that doesn't help you might need to buy a replacement width coil (make & model specific!) from Bob Roberts. The replacements are not glued so you can easily adjust them.

Check Bob Roberts' monitor width cap page. If the picture is too wide you need to change the value of the width size determining capacitor as described on Bob Roberts' site.