Symptoms:
- Horizontal streaking on the LCD screen - pixels seem to be displacing themselves left-right by up to 20 pixels.
- very little streaking is apparent at the left edge of the screen, then it gets steadily worse toward the right edge, where text becomes illegible.
- The displacement is constantly changing, so it looks like the screen is shimmering (ie, the picture is not just distorted, it is ongoing flickering.
- problem shows up gradually - might see nothing for a half hour after powering up, then gradually flickering starts and gets progressively worse.
- The first time I saw it, it started quite accutely, then wiggling the screen it went away, but that has not helped since, so it might have just been coming and going regardless my wiggling.
- external monitor does not display the problem
- when I activate both monitors at once (either cloned or independent displays) the problem instantly appears at its worst level, even if screen was fine before that
- Even when cloned, the external display looks fine, while the laptop screen is showing the same image with distortion.
- Changing screen resolution does not help.
- Refresh rate is 60Hz with no other options
The problem first started when I had the laptop plugged into a power bar that I think has an unreliable current - eg when moved, a light plugged into it goes on and off. But it has persisted when not plugged in. The only other thing I can think of that might have damaged it is that I cleaned it with some lens cleaner, and maybe some ran down into the case? But that was a while back.
Everything was working fine for two months (with external display too), I did not change any software or display settings or drivers. Running Windows XP, the video card is an ATI Mobility Radeon 7500, the screen is a 1400x1050 UXGA display
A "screenshot" (taken with a digital camera): http://djnr.ca/IMG_3601.JPG
Very strange, I was jostling the laptop to plug in the USB to upload the picture, and the problem went away, both displays are active and looking fine. Still, I am guessing next time I bump it it will come back. Don't you hate it when you bring your PC in for repairs and it works fine when you try to demonstrate the problem. Then you take it home and the problem shows up again...
Anyhow, any ideas what could cause this? The screen? the video card? power supply? bad connections somewhere? Anyone seen this kind of problem?