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Strange question... Occasionally, on my LCD screen, pixels that should be black flicker rapidly and constantly between black and green, about 4 flickers a second.
The crazy part is, unlike dead/stuck pixels, they are relative to content on the screen and move with it.
For example, I might be looking at a web page with a picture that has lots of black. There might be a couple of green flashing pixels in that black that shouldn't be there. I scroll the page, and the green flickering pixels move with the image. It seems that everyphysical pixel is fine, but somehow something interprets part of the image in a way that causes flickering green...
It's not just in a web browser. My first thought was to blame a trolling blogger cunningly uploading an animated gif that simulates a failing pixel... but it happens in a wide range of applications. It seems to occur randomly, other than that it seems to only occur in areas of pure black, and it's always pure 100% green.
It happens rarely enough that it's not a big deal, but it's such a strange problem it bugs me. I can't find any info on anything like this. I'm not even sure if it's hardware or software.
Any ideas? (windows 7 laptop connected to LCD by DVI to HDMI cable)
6This sounds to me like it might be a video RAM problem, but I've never seen anything that's behaved quite like this. – Shinrai – 2012-04-03T22:25:22.260
2I've seen a similar problem using a G5 Powermac driving a Cinema display. Shapes on screen develop odd green borders. Turning off the monitor briefly and back on again cures the problem. It's happened only a few times in the seven years I've had the gear. I agree with @Shinrai -- video memory corruption seems the best fit for the symptoms. – Kyle Jones – 2012-04-03T23:14:03.227
Sounds like a good theory. It's an old laptop running a hefty HD screen and a VGA screen at the same time - could it be a symptom of overloaded video RAM? – user56reinstatemonica8 – 2012-04-03T23:37:34.867
2I wouldn't say 'overloaded', per se (either it's in use or it isn't) but possibly it's getting too warm or something like that. The only remedy probably would be replacing the laptop and I doubt it's worth bothering. I'm still not 100% convinced (or this would be an answer instead of a comment) but I just can't think of any other explanation right now. – Shinrai – 2012-04-03T23:49:09.877
1For others who are experiencing similar problems: apart from broken VRAM and overheating, these video memory corruption symptoms have also been associated with the card experiencing drops in voltage. So if that's something you haven't checked yet, it might be your PSU that's giving out. – Daniel Saner – 2012-07-21T04:25:15.197