Monitor Screen Keeps Shaking

Eric S. Johansson esj at
Thu Sep 8 13:27:21 UTC 2005

Soo-Hyun Choi wrote:
> Hi,
> I've got a machine for dual boot with WinXP and Ubuntu Hoary 5.04. If
> I boot with WinXP, the screen just works perfect. My monitor is
> Philips 170S (LCD screen), and VGA card is Radeon 7000 series.
> But if I boot with Ubuntu, the screen is keeping shaking and it's very
> unstable. (i.e., the screen is keeping tiny trembling and flickering.)

which way is it shaking, up and down or left and right?
> Because the screen just works perfect under WindowsXP with same screen
> resolution, I don't think the problem is in the LCD monitor or the
> graphic card.

I agree.  It's probably the drivers.  If it's shaking up and down that 
it's your vertical sync.  Left and right is your horizontal sync.

are you using the digital video input or are you using analog?  Is the 
display resolution the same as the card resolution?  IE if the screen 
has 1280 by 1024 pixels, is the video card generating the same 
resolution?  LCDs get funky if they are driven with any resolution other 
than the native one.  The most common artifact is display fuzziness.

> Did anyone have similar problem like me? and got any idea to sort this out?

only with a CRT that had a magnet or speakers next to it.


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