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Mass Hysteria

macrumors regular
Original poster
Jan 31, 2005
162
1
Hi all

I noticed that when I have another monitor connected to the laptop and move the mouse pointer over to the external display, it moves slightly.

I don't mean that the display physically moves across the desk, that would be a bit concerning to say the least, but I mean that the image on the screen seems to shift by a pixel or so left to right.

It used to shift up and down too, but a permissions fix has repaired that.

I also noticed that if I start up from the 10.4 dvd with and external monitor connected, the problem goes away.

any ideas?
 

mkrishnan

Moderator emeritus
Jan 9, 2004
29,776
15
Grand Rapids, MI, USA
What kind of external display do you have? Is it an LCD, Plasma, CRT, or ... ? Are you sure you're running it at its native resolution? You see this kind of thing sometimes when you are using a digital screen (LCD or Plasma) with analog inputs (VGA, component, etc) and you are not running it at its native resolution.
 

Mass Hysteria

macrumors regular
Original poster
Jan 31, 2005
162
1
really strange now!

yeah, I know what you mean, I used to have problems with one particular lcd at work. It used to wobble left to right whenever I moved the mouse.

But this particular problem occurs with any connected display now.

I just disconnected the external display, and the shifting now occurs top to bottom and not left to right.

In fact, it's not really shifting, when I move the mouse pointer to just over half way down the screen, the display shrinks back by one pixel from the bottom.

I think that this is where the display should be, since any text on websites etc instantly becomes sharper.

It's not the end of the world or anything, it's just slightly annoying!
 

mkrishnan

Moderator emeritus
Jan 9, 2004
29,776
15
Grand Rapids, MI, USA
Can you try this: If you do something relatively dynamic -- play a video, view web pages, etc, where lots of stuff onscreen is changing -- do you get more of this jitter? If so, it might be that you have a bad video cable (unless, when you say that it happens with any display, you're actually also trying multiple cables).

If not, ... hmm... that's a very odd problem. I've seen it before, but only many years ago on much older technology. I thought it had pretty much become an anachronism in the modern age.
 

Mass Hysteria

macrumors regular
Original poster
Jan 31, 2005
162
1
when I have an external display connected:

If I move the mouse from left to right, I get to a point about 9/10 of the way across the powerbook screen and both screens shift by one pixel to the left.

If I carry on moving the mouse across the external monitor, I get to another point about halfway across and both displays shift by another pixel to the left.


when I have no external display connected (ie just the powerbook screen):

If I move the mouse from top to bottom, I get to a point halfway down, and the screen shrinks back one pixel from the bottom and all text on the display becomes sharper (like it should be).

This effect is the same if I am playing media etc or just viewing the finder.

I guess it's a software thing since it does not happen if I am running the powerbook from the 10.4 dvd.

I've tried repairing permissions and repairing the disk from disk utility but the problem is still there. I'm just not sure what I can do to fix it, any ideas??
 
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