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krye

macrumors 68000
Original poster
Aug 21, 2007
1,606
1
USA
I got my Mac Pro in March. So I've had it for a good 6 months. In that time, at least 3 times my 30" Cinema Display has shown some sort of video glitch. I'm convinced that it is the 8800, and not necessarily the Cinema Display.

What happens is, out of the blue, and for reasons I'm not sure of, I will get a strange pattern of brightly illuminated pixels on the display. They are "fixed". In other words, If I move and image around on the display, those pixels are stuck and do not move with the image. Also, if I take a screenshot, they do not show up on the screenshot at all. I had to try and take a picture with my camera to show you guys. A reboot and/or logout/login fixes it. I think it is some sort of bad video RAM or something. I've already upgraded to 10.5.5 and it did it again last night. I'm pretty sure it was the result of DVD player crashing. But then again, I don't know if DVD player crashed because of a video glitch. The DVD was kind of scratched up (netflix) and the computer did have problems reading it. DVD player beach balled when I tried to skip a chapter so I have to kill it. That's when I noticed the display was all screwed up.

3 times in 6 months isn't a huge deal, but it does make me worry about a pending hardware death of either my display or video card.

Anyway, have you guys seen this? Is it a cause for concern? Is my 8800 on the way out, or is it most likely some sort of driver or app hiccup that isn't really a big deal?

In these picture you can see the randomly scattered light green pixels. It's almost as if a color has been swapped out.

2864581319_f65b4a9db7_b.jpg


2864581317_8bdb812bbb_b.jpg


2864581313_eeae326eb1_b.jpg
 
I had a problem with bad video Ram (or more precisely, a wrong ROM for a 9800Pro) and the artifacts I saw appeared were present on screenshots too.

Your problem reminds me of a bad contact in the display of my old G3 Powerbook. The GFX card worked fine but the video connection to the display was faulty.

I would check the display cable and whether it's connected correctly to the graphics card (screws tightened?).
 
I had a problem with bad video Ram (or more precisely, a wrong ROM for a 9800Pro) and the artifacts I saw appeared were present on screenshots too.

Your problem reminds me of a bad contact in the display of my old G3 Powerbook. The GFX card worked fine but the video connection to the display was faulty.

I would check the display cable and whether it's connected correctly to the graphics card (screws tightened?).

If that was the case, wouldn't this happen more often that once every 2 months? Also, I can't be certain, but it think it was the result of DVD player crashing.
 
I've had a loose cable cause that - except it was the color red. It was highly intermittent - and I thought it was a dying LCD - turns out, it was the cable in my case.
 
I've had a loose cable cause that - except it was the color red. It was highly intermittent - and I thought it was a dying LCD - turns out, it was the cable in my case.

In that case, I'll have to tighten up the card to be sure.
 
If that was the case, wouldn't this happen more often that once every 2 months? Also, I can't be certain, but it think it was the result of DVD player crashing.

Computers problems can appear far more organic (random) than we give them credit for.
 
It's a common fault with the 30" Cinema Display. There is a MASSIVE thread on Apple Discussions about it, but after 3 years still no solution.

I've had 3 30" Displays all with the same issue and have given up trying to get a good one now. When it happens, I just reboot and it usually goes away. The same problem occurs when the display is plugged into a PC (so it's not just a Mac issue), and it happens with both Nvidia and ATi cards. It can happen at boot time (you see green pixels around the grey apple logo or around the DOS characters on a PC), so it's not driver related. It happens pretty much every time the screen goes into sleep mode, so that would seem to indicate it might be power related?

I've just configured mine not to sleep. :rolleyes:
 
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