MAMEWorld Forums - Hardware - Re: Monitor issue

> Recently I got a free cab from someone nearby me. It's been working ok and I've put
> some work into it to fix it up, but the monitor has a strange thing going on with it.
> Basically in the morning it's fine, works great, but gradually over time the monitor
> lightens up and lines begin to appear on the screen like the picture attached, also
> it seems to get blurrier after time. It dissapears after being off for some hours. I
> assume it could be a cap issue, but I'm wondering if anyone has a better idea of the
> problem.
>
> It's not amajor issue since it's not very noticable in game, but y'know.
>
> Black: Portions of screen not used.
> Dark Grey: Poritions of screen used despite supposed to be black ( and it is very
> noticable).
> Light Grey: Lines that appear, faintly.

grey lines = retrace lines.

It's possible that caps are causing the problem, but it's more likely that the flyback and or screen/focus pots are the issue. Turn the monitor off, rotate the screen and focus pots back and forth a few times. put them back relatively close to where they were. Turn the monitor on. With the help of a mirror or a second person, try to adjust the focus and screen pots with a wooden dowel or a plastic screwdriver. You should be able to bring the screen control back enough so the retrace lines disappear and black looks black. Adjust the focus until the picture is as crisp as it can be.

If the picture still changes over time, you can try caps, flyback, or even a yoke. If there are any other symptoms in the picture like blooming or waves, now is the time to say so.