When flashing white distorts a picture... who's to blame?

john rainbo

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When flashing white distorts a picture... who's to blame?

When you have a white image flash, or just show up, and that will sort of make the rest of the picture react... how does one fix that? Is that a cap or something, or is that the tube at fault?
 
Likely voltage regulation related... I believe you're describing blooming.

What monitor is it, and does the whole image sort of get bigger/smaller, or does something else happen?

DogP
 
I'm speaking in general, let's just say standard wells monitors. I've seen it countless times on countless monitors. Just wonder what makes this happen, and how could it be fixed? I'm speaking of when you see a white image on the screen, and then the rest of the screen suddenly and slightly increases/decreases in size. If the white image stays on the screen, the screen looks fine. I'm talking about a flashing background, or white "press start" or something of that nature that makes the rest of the picture slightly change.
 
I don't know - I'd blame the game for flashing the screen so fast. What games do that, anyway? I can't think of any.

The culprit is poor B+ regulation. It could be a bad voltage regulator, it could be a bad filter cap, or, it could just be a design flaw. A certain amount of picture-changing-size is unavoidable. As the beam current increases (lots of bright stuff on the screen), the B+ supply is taxed more, and if it sags a bit, then the picture changes size.

Many television sets do the same thing - next time you're watching TV, pay real close attention to changes between light and dark scenes, a small amount of image size changing is pretty common. Older (cheap) PC monitors had the same problem, but newer ones are made such that this doesn't happen any more. They're also a lot more expensive and complicated than video game monitors or TV's.

-Ian
 
To answer your question, lots of games have the color WHITE IN THEM! lol, but seriously, flashing health bars. PRESS START. INSERT COIN. Things like that.
 
The link I posted explains why it happens. Normal white on the screen won't be affected. It's when the entire screen - or a portion of it - is being driven extra....
 
Kortek chassis shipped with early PiU GX cabinets had this issue right out of the factory. All of them. IIRC there was a service bulletin and the fix involved replacing the flyback. Take that as you will.
 
here we go again steve is huo-ing up his games again lol..

when caps go dry the b+ isnt regulated as nicely and so form regular screen to flashing white youll see the pic grow and shrink as thats happening.. i think thats what your describing correct?

now will caps fix it? sometimes yeah but to a point, they all do it. Some models worse than others.
 
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