Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: Numbski on December 24, 2006, 11:15:24 am
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I'm only guessing from pictures that this is indeed a K7000. All of the manuals and schematics appear to match.
The picture is just slightly too wide. I've tried and tried to get the picture more narrow in software using my arcadevga card, but nothing doing. I can't get it.
I tried adjusting it more narrow using a plastic tool from radio shack. I can see the ferrite (sp?) slug turning in the coil, but there's no impact on the picture width no matter which way I turn it.
From searching, it appears that this means the coil needs to be replaced. Is this correct? The monitor was used in an old ChaseHQ cab, has composite sync running to just one of the sync pins rather than it being split out. I'll probably change that soon but I don't think that's the problem with the horizontal width. Colors are relatively crisp, but if I replace that coil I'll probably do a cap kit on it just for the sake of being sure I'm getting good performance out of it since the board says 1986...I'm better it's never had a cap kit done on it.
So am I right about the coil? Anyone have a source for it?
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http://homearcade.org/BBBB/wc.html
Bob Roberts sells the correct replacement coil for your particular model on his parts page.
Remember that the range of a width coil is set by the value of the width capacitor. Bob Roberts sells an assortment of width capacitors on his parts page and click on "Cap Kit Price List" -> "Monitor Width Cap Kit". A width coil generally only has an on-screen adjustment range of 1/4" on each side max. Chances are your coil is fine and just the width capacitor (C38 on a k7000 which is the value of .39 uf @ 200 volt) needs changing. Sometimes the monitor manufacturer will glue the adjustment slug inside the width coil in place at the time the monitor was manufactured to prevent you from 'playing' with it. Only use the special plastic width coil adjusting tools to adjust it. If the coil slug is glued, sometimes heating it with a hair dryer softens the glue enough to adjust it.
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Well, I cheated on the tool. I have a radio shack plastic tool that was close. I heated it (the tool) with a lighter, and then pressed it into the slug and let it cool there. Ta da! Perfect tool. ;)
I turned it as far clockwise as I possibly could with my wife watching the screen. It shrunk down a little bit, but not nearly enough. You may be right, it might be just another cap that needs replacing. I appreciate the help. Was driving me nuts. If it works, give me a paypal address to send you beer money (or whatever it is you drink). :D
ERRRR....btw, the site you linked to is cyber-squatted. There's nothing there!
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Edited URL.
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And here's the link to the page about adjusting the value of width capacitors:
http://therealbobroberts.net/width.html