my screen is shaking

[johnoh]

Here's a weird one. I have an old Futura 19" monitor. It used to be on a P3 550mhz, ATI rage pro system, where it would produce this shaking effect. Its like every pixel is moving a fraction of a millimeter back and forth maybe 5 times a second. I started using the monitor on another system and the shaking went away, an underclocked amd t-bird running at 1.05 mhz using an Inno3d Ti4200 card. The system is underclocked because it is unstable at 1.4ghz, which is what its supposed to run at. Well today I switched power supplies (300w replacing a 300w) on that system, thinking maybe that was the problem with the 1.4ghz stability. Sure enough the processor is now stable at 1.4, but the screen is shaking again. Anybody got any ideas what is going on?

John A

 

[phsstpok]

That's usually caused by electrical interference. An AC power cord running parallel to the video cable, a power transformer near the monitor, any electrical appliance near the monitor, or even one monitor next to another monitor can cause the problem.

Sometimes changing the refresh rate can reduce or even eliminate the problem.

<b>I type sixty words per minute. Ten are spelled correctly.</b>

 

[johnoh]

Thank you. I changed it from 85hz to 75 hz and that fixed the shaking. Of course now I have flicker to deal with, but I'll play with it and try to find the balance point. There are no cables or transformers in the way that I can see, and there is another monitor right next to it but thats always been there.

John A

 

[phsstpok]

You should test with that other monitor. The combination of refresh rates on the two monitors might be the source of the problem. Try turning the second one off and retesting.

For a power cord to be the cause of the problem it would almost have to run side by side the entire length of the video cable. The monitor's own power cord can even cause the problem.

I ran into the problem with a power "brick" for an old deskjet printer. I also have a box fan that causes severe "shaking". Even 5 feet away from the monitor I can still see it. The "brick" had to be almost touching the monitor for it to be a problem.

Some monitors are extremely sensitive to this kind of interference.

Other common sources include electric heating, florescent (sp?) lighting, stereo amplifiers, televisions, and more which I can't recall.

<b>I type sixty words per minute. Ten are spelled correctly.</b>