Wacky Mac Screen


At the Blogger Meetup, I showed Blankbaby a weird phenomenon on my new Macbook:


If you look carefully at the screenshot above (or click on the picture to go see it on a larger size at Flickr), you’ll notice that there’s some weird degradation around the popup menu in the middle of the screen. Here’s a close-up:

Screenshot closeup

This actually happens with some regularity on my screen — though, it refused to show up at first at the Meetup. Cleverhack suggested I stress out my computer some to get it to do it, so I opened up every application on my dock, closed them, and pretty soon, it started happening. Here’s another screenshot:

Another screenshot

As you can see, it can get pretty bad. If you look carefully at the above screenshot you’ll also notice a weird color band running across the top of the desktop picture. You can see it better here:

Screenshot with band in background

[Update! When my Macbook comes out of sleep I sometimes see this degradation on the Dock bar:]

Dock degradation

[And a closeup:]

Dock closeup

Everyone suggested I back everything up and go to an Apple store immediately. Beyond that, they didn’t know. Anyone else having this problem?

8 thoughts on “Wacky Mac Screen

  1. John Russell

    Seems like a problem with the rendering of shadows. With the exception of the dock rending problem, all of the static seems to appear where shadows normally would be.


  2. Hey there, this is a fairly common problem among MacBooks, and has been reported by many users in Apple’s Discussion Forums: http://discussions.apple.com/thread.jspa?messageID=2489169

    I also experience the problem once in a while – seems to only happen when I’m really taxing the system (i.e. using up all of the available 2 GB of RAM that I have). Seems to have something to do with shared memory and the video card, but I can’t reproduce it reliably.

    I think it’s a software issue, and I believe someone in the thread said Apple is aware of the issue and is planning a fix for 10.4.8.



  3. Are you using secure virtual memory (security preference pane)? I had that appear on my first MacBook (now replaced due to optical drive problems) and it didn’t reappear after deselecting it.


  4. Tom, I’m glad you were able to get screenshots. 🙂 I am amused though (in a sick, used to work in tech support kind of way) that there’s several suggestions in this thread and on TUAW.

    In order of ease, I’d try the disable virtual memory idea first and then wait for the 10.4.8 update. Here’s hoping it’s just a shared memory issue and not hardware related.


  5. 3Dman

    I had the same problem. It would manifest itself after waking up from sleep every time. I then installed the latest firmware upgrade in order to install Boot Camp and the problem went away…..


  6. I would do an archive and install preserving user setttings, then run software updates. A lot of times, these weird window-drawing things can actually be software issues. Of course, do a full backup before doing the above!


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