Vertical Monitor can't reduce image size

MaxAsh

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Hello - I recently picked up a Pacman cab and it looks like there's a "Videomaster13" (Kortek) 19" monitor in there. Picture/colors/etc all look great, but I'm having one issue:

The horizontal width (vertical height for this monitor orientation) won't reduce any further. The image fills the whole screen perfectly, but the plastic Pacman monitor shroud is smaller than the full screen size, meaning it cuts off about a half inch or so around the perimeter of the screen. Normally I would adjust the image to "shrink" it down to fit within the plastic shroud area, but I haven't had any luck. I can adjust the vertical size (horizontal in this orientation) just fine, but the height won't shrink any further.

I thought about messing with the Horizontal Width coil (since I assume in this orientation it would adjust the vertical width for me), but I need to essentially shrink the image about an inch. I've been reading about the width coil and I've never had to adjust it. I want to make sure I'm considering the right thing considering how touchy that area seems to be.

Thanks
 
That is correct. To reduce the vertical size on a vertical oriented monitor, you have to adjust the width coil. You will absolutely need to have a plastic TV adjustment tool as the width coil requires a hex-shaped instrument to turn it. If the game is on and you use metal, the metal allen wrench will heat up tremendously and not make you feel all that great.

Of course, you can use metal instruments if there is no power to the chassis, but if the monitor is running you're going to need a plastic allen wrench. (I actually made one myself using spare model kit plastic sprue and an old width coil that I used to mold the melted plastic).

Keep in mind that the width coil won't make huge changes to the width of the image. It really just refines the edge. If you post some photos here, someone with greater knowledge than I will be able to let you know if it can be adjusted via the width coil.

If the width coil can't make the adjustments you need, then you may need to think about a change to the capacitor that controls the horizontal width.
 
Thanks for the reply Jdurg. I'll have to pickup the plastic tool set. Out of curiosity, is there a specific direction (clockwise vs. counter clockwise) that's standard for stretching vs. shrinking the width via the coil? Also, I get the impression that a single rotation is very minimal change, and that I'll be performing a lot of turning to get a full 1" or so of overall width reduction. Would that be accurate?
 
Thanks for the reply Jdurg. I'll have to pickup the plastic tool set. Out of curiosity, is there a specific direction (clockwise vs. counter clockwise) that's standard for stretching vs. shrinking the width via the coil? Also, I get the impression that a single rotation is very minimal change, and that I'll be performing a lot of turning to get a full 1" or so of overall width reduction. Would that be accurate?

Correct. I can't recall which direction does what, but the best way to learn is to just try it out. :) So make sure you have someone who can help you with the visual aspect and let you know if it's growing or shrinking.

And yes, you'll need to spend a bit of time there as one turn won't do too much. But it's good that you've already done your research on this. Makes it easier for others to help you troubleshoot. :)
 
I ordered the proper tools, should be here in a few days. The width coil on this board is a little different than others I've seen. Normally they are white, often perpendicular to the board in my experience. This one is black, and seems to be laying flat on the board next to the adjustment pots. I'll have to take a pic later.
 
Success! The plastic adjustment tool did the trick. I also have a tilt issue, but I'll post separately about it since it's different. Thanks all for advice on this one.
 
Success! The plastic adjustment tool did the trick. I also have a tilt issue, but I'll post separately about it since it's different. Thanks all for advice on this one.

if your image is tilted that is probably a yoke adjustment. loosen your yoke and turn it slightly but make sure the power is off to be safe and also make sure the yoke only turns and doesn't slide in or out otherwise you will have another image problem to adjust.
 
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