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Bernhard Pieber

Q: Flickering green and blue pixel problem

Here is my report on the flickering green and blue pixel problem which others have also reported:
- Green sprites or snow on ATI X800
- 30 inch with flickering blue pixels
- 20 " Cinema Display with vertical green line
- New 17" PB + 30" Cinema. Random Pixel Problem
- 30 inch screen issue?

I got a brand new Dual 2.5 GHz PowerPC G5 with a nVIDIA GeForce 6800 Ultra graphics adapter with 256 MB VRAM and a 30' Cinema Display. During original setup after about 20 minutes I discovered flickering pixels on the desktop background. In the top and center area of the display they are green and in the bottom area blue. When I change the desktop background from Aqua blue to a solid color they go away.

We talked to friends who have the same hardware configuration. They had the same problem with one of their computers and solved it by replacing the nVIDIA graphics adapter. We talked to AppleCare and they sent us a replacement graphics adapter. I installed it and first it looked as if our problem had disappeared. However, after working for an hour the problem appeared again. This time there were more blue pixels than green one in the bottom area of the screen.

To find out the source of the problem I did some tests:
1. It also happens if I play DVDs.
2. The longer I work the more pixels I get. Flickering pixels turn permanent. Over time it starts looking like a night sky with blinking stars.
3. When I turn off the display for some seconds and turn it on again first the pixels are gone but after some seconds they begin to appear again on the exact same place they were before.
4. After a certain time pixels also appear in the dock and in the icons on the desktop.
5. If I move a window near the pixels they disappear as soon the window shadow moves over them.
6. The pixels on the desktop background vanish if I change the desktop to a solid color.
7. I made screenshots of the Aqua blue and Aqua graphite desktops and open it using Preview. The flickering pixels appear there, too.
8. On the Aqua graphite background there are much more green pixels than blue ones.
9. If I move the Preview window containing the screenshot of the Aqua blue and graphite backgrounds the pixels jump. If I move the window 1 pixel to the right, the green and blue pixels stay in the same area but change position. If I move the window back 1 pixel to the original position, the green and blue pixels change back to the original configuration.
10. If I find myself an easy to recognize configuration of flickering pixels and move the window exactly 8 pixels to the left or to the right the configuration reappears!
11. Even after a restart the pixels seem to appear on the same places of the background.
12. When I first discovered the problems there were two green pixels in the center of the screen. Even after I replaced the graphics adapter with the new one I at least once saw two green pixels which appeared to be at the exact same position as with the original graphics adapter.
13. Joggling the graphics adapter connector cable does not affect the flickering and/or position of the pixels.
14. Others reported it only appeared after they updated to 10.3.8.
15. Others reported it also happened with ATI graphics adapters.
16. Others reported the problem went away with ATI graphics adapters when they updated their ATI drivers.
17. Sometimes I have green pixel configuration directly on the left side of a window over the Aqua blue and graphite desktop backgrounds. They all are on a vertical line in the shadow of the window. When I move the window down or up the green pixels stay at the same place on the background. If I move the window one pixel to the left or the right, the configuration changes.
18. Two times the problem suddenly disappeared completely and only slowly reappeared minutes later.

Some possible causes:
C1: Hardware defect of the graphics adapter.
C2: Hardware defect of the computer's mother board.
C3: Software problem of the graphic adapt

Posted on Nov 9, 2005 6:58 AM

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Q: Flickering green and blue pixel problem

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  • by Michael Carey2,

    Michael Carey2 Michael Carey2 Jun 7, 2005 9:34 PM in response to Michael Carey2
    Level 1 (10 points)
    Jun 7, 2005 9:34 PM in response to Michael Carey2
    An Update... I called AppleCare. They said this was a known issue and there was a knowledge base article on how to fix it. Basically the fix is to replace the monitor.

    I packed up my computer and monitor and took it down to the Apple store where I purchased it. I also purchased an upgraded video card so I now have the NVIDIA GeForce 6800 Ultra DDL. They took my monitor and gave me a new one. We hooked the system up before I left. We let it run for about 3-5 minutes. I could not see any of the errant pixels. I took the system home. Set it all up. After about 30 minutes of use, the pixels reappered. It is not hot in my house, I have air conditioning and keep it nice and cool. Also, this is the Denver area so it is not humid here.

    I busted out my camera and took pictures.

    I'm going to make one more trip to the store... I'm going to hook my system up as is and let it run for an hour. Then I'm going to see if the pixels appear there.
  • by Dan Haupt,

    Dan Haupt Dan Haupt Jun 9, 2005 6:51 AM in response to Dennis Robinson1
    Level 4 (3,395 points)
    Jun 9, 2005 6:51 AM in response to Dennis Robinson1
    We seem to have a 30" display that may have "fixed itself" as well. It had sparkles on two different computers, and now does not seem to have them anymore.

    -Dan
  • by Michael Carey2,

    Michael Carey2 Michael Carey2 Jun 10, 2005 2:10 AM in response to Michael Carey2
    Level 1 (10 points)
    Jun 10, 2005 2:10 AM in response to Michael Carey2
    An update… My second replacement 30-inch monitor is experiencing this problem as well. I honestly don’t know what I am going to do. I paid over 8000.00 dollars for the entire computer system. This is the most money I have ever spent on a system.

    I spent the entire afternoon at the Apple Store in Denver testing this monitor. It did not have flashing pixels in the store. The pixels appeared the second day after brining this new monitor home. What am I supposed to do, drive to Denver every morning and pick up a new monitor for the day?

    I’m so discouraged and disgusted; I am going to bed and decide what to do tomorrow.
  • by C Ellingson,

    C Ellingson C Ellingson Jun 11, 2005 5:05 AM in response to Bernhard Pieber
    Level 1 (0 points)
    Jun 11, 2005 5:05 AM in response to Bernhard Pieber
    As posted earlier I have had the same problem. I recently changed from the Apple Desk Top Patterns, to some floral jpg's that change every 5 minutes. I have not had the problem in the last 4 or 5 days.

    At the moment, the problem seems to be related to the particular desk top back grounds that I choose....very strange.
  • by Michael Carey2,

    Michael Carey2 Michael Carey2 Jun 24, 2005 1:48 PM in response to Michael Carey2
    Level 1 (10 points)
    Jun 24, 2005 1:48 PM in response to Michael Carey2
    An update: I called the AppleCare line. They called the Apple Store in Denver. The Apple Care CSR told me the store would unpack a monitor and test it for several days, then call me back. A couple of days later, I called the Apple Store and spoke to one of the support people there. They told me they knew about this and were in the process of testing a monitor. They said they wanted to test it for several days. I didn’t hear from them for a week.

    I called today. The person I spoke to said she was not aware of this. She gave me the name of some customer relations person at Apple. She said this person would call me within an hour. We shall see.

    I am very close to boxing this entire thing up and getting a refund.
  • by Michael Carey2,

    Michael Carey2 Michael Carey2 Aug 7, 2005 8:37 AM in response to Michael Carey2
    Level 1 (10 points)
    Aug 7, 2005 8:37 AM in response to Michael Carey2
    An update: I called the person at Apple. They called someone at the Apple store. The Apple Store burned through all their stock testing monitors for me. They got stock from a nearby store. They burned one in for a day or so. There were no flashing pixels (or so I was told).

    I took my monitor back and exchanged it for this tested monitor. Took the new monitor home and used it for a couple of weeks. The pixels have returned. However they are not as bad as before. I honestly cannot predict when the pixels will appear. Sometimes when the monitor is initially powered up. Sometimes after I have used it for several hours. Sometimes I can turn off the monitor for a few seconds and the pixels will disappear, sometimes I must turn it off for quite a while.
  • by Lance Mcvickar,

    Lance Mcvickar Lance Mcvickar Aug 25, 2005 2:12 PM in response to Michael Carey2
    Level 1 (100 points)
    Aug 25, 2005 2:12 PM in response to Michael Carey2
    I have had the same problem for a long time,30 inch nvidia 6800 ultra. I have a 22 inch display hooked up as well and it never gets flickering pixels. I think it has something to do with the duel dvi. I hooked my monitor up to my older ATI 9800 pro and though the resolutions where low I never got any bad pixels. The Apple store has a 30 inch on all day and it never has the problem. It is running on the ATi 800 so maybe it's a video driver problem not hardware. I still don't know and Apple has not come up with a fix. They had my monitor over night on their system and they had no problems. It's very frustrating not knowing after you spend all the money. And as I type I see the little green devils....
  • by Mountain/\Ash,

    Mountain/\Ash Mountain/\Ash Oct 11, 2005 8:40 AM in response to C Ellingson
    Level 1 (55 points)
    Oct 11, 2005 8:40 AM in response to C Ellingson
    I too am having a similar problem with red pixels on black sections of background/dekstop images (although this may just be that it is easier to see on black).

    Although unlike other users (here and in the topic titled '30" Display Flickering/Dancing Pixels') I am on a 20" G5 2 GHz iMac and using the latest (10.4.2) version of Tiger.

    I also sometimes get dotted/spaced travelling lines of white pixels when watching/previewing movies in iDVD.

    I believe this is a software issue as it seems to depend on what the screen is currently displaying.
  • by Nick Harvey2,

    Nick Harvey2 Nick Harvey2 Nov 9, 2005 6:58 AM in response to Bernhard Pieber
    Level 1 (0 points)
    Nov 9, 2005 6:58 AM in response to Bernhard Pieber
    We have the same occasional flickering green and blue pixel problem on a G5 dual 2.5Ghz (10.3.9) with a 30inch Apple display.

    The fix is to open the the monitors preference pane and change the colour setting from "Millions" to "Thousands" and then back to "Millions" again.

    Hope this works for other people too.

    Regards,

    Nick
  • by Berek,

    Berek Berek Nov 23, 2005 7:36 PM in response to Nick Harvey2
    Level 1 (5 points)
    Nov 23, 2005 7:36 PM in response to Nick Harvey2
    Having similiar problem on my system:

    G5 2.7 Dual w/ ATI Radean 9650
    22'' Apple Cinema Display w/ACD

    I am using a Gefen ADC/DVI repeater to convert from DVI to ACD. This also amplifies the signal. I am using a Dr. Botts extention, but, I have the same effect without the extention connected..... Not sure it is the DVI to ACD unit or not. I notice the green noise pixels randomly anywhere the monitor displays black... Become very noticable when the screen saver becomes active as the entire display will produce this green noise.

    What the !@#$#$?
  • by Berek,

    Berek Berek Nov 23, 2005 7:46 PM in response to Berek
    Level 1 (5 points)
    Nov 23, 2005 7:46 PM in response to Berek
    Having similiar problem on my system:

    G5 2.7 Dual w/ ATI Radean 9650
    22'' Apple Cinema Display w/ACD

    I am using a Gefen ADC/DVI repeater to convert from
    DVI to ACD. This also amplifies the signal. I am
    using a Dr. Botts extention, but, I have the same
    effect without the extention connected..... Not sure
    it is the DVI to ACD unit or not. I notice the green
    noise pixels randomly anywhere the monitor displays
    black... Become very noticable when the screen saver
    becomes active as the entire display will produce
    this green noise.

    What the !@#$#$?


    Just wanted to add, I do not have this problem, running all the same connections to my G4, and the only thing I add, is an additional DVI to ADC adaptor to plugin to my ADC port on my G4
  • by Mountain/\Ash,

    Mountain/\Ash Mountain/\Ash Dec 6, 2005 3:13 AM in response to Mountain/\Ash
    Level 1 (55 points)
    Dec 6, 2005 3:13 AM in response to Mountain/\Ash
    Just wanted to add that I have an image that triggers the red pixels and a (badly shot) video of it occuring. If anyone from Apple wants these please contact me.
  • by John Schank III,

    John Schank III John Schank III Dec 9, 2005 6:50 PM in response to Bernhard Pieber
    Level 1 (79 points)
    Mac OS X
    Dec 9, 2005 6:50 PM in response to Bernhard Pieber
    Hi there,
    I want to add that I also have this problem. Green pixels, lots of them, and they aren't random. The seem to follow some sort of color boundaries. They move when I move a window that has them as "fringing" also I get blue interference on occaision. (like a cheap TV image effect)

    I have a dual monitor set up (clear bezel 23" cinema display and 30" cinema display) using the NVidia Quadro FX 4500. I also spent a wad on this system.

    For me, turning the display on and off a time or two will solve it for a while. (the system preferences, for displays, display power button turns the display on and off)

    Seems to occur after the screen has been blanked in software (sleep)

    Finally, The power button on the monitor DOES NOT turn on my system. (of course with the display preferences set correctly). This may be a result of using 2 monitors. Does anyone know?

    Thanks,
    John Schank

    P.S. I too, am really angered that I paid 12K for this system and it has this kind of persistent problem
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