Captiosus77

Q: Old Powerbook Ti (M8859LL/A) Display Wonkiness

Howdy all.

 

At a recent estate sale, I picked up a box labeled "random electronics" on the cheap and, to my surprise, I found an old PowerBook G4 Ti buried at the bottom of it. Other than being dusty from being packed away, it seemed in decent condition. After a bit of TLC, and a fresh install of retail Tiger, it runs great, but it has this strange bit of display wonkiness.

 

It's hard to describe, so I'll drop some images here at the bottom for viewing. I've dealt with image persistence on various LCD screens I've had to support and fix in the past, but this seems more nefarious than simple image persistence. Indeed, trying to "white out" the image has yielded no results. The effect is too static for me to suspect the GPU as it displays on screen just fine. I haven't tried hooking it up to an external display yet just to be sure, however.

 

I'd love to hear some opinions on what this may be. Even if it can't be fixed, it's still useable and it's a nice little machine to have while just lounging around the house.

 

Here's links to two images:
Image 1: While looking at it as if using it with medium backlight.

Image 2: Looking at it from an elevated position, on a slight angle.

 

Thanks in advance!

PowerBook, Mac OS X (10.4.11), M8859LL/A

Posted on Jan 11, 2012 1:37 PM

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Q: Old Powerbook Ti (M8859LL/A) Display Wonkiness

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  • by Braby,Helpful

    Braby Braby Jan 11, 2012 3:28 PM in response to Captiosus77
    Level 4 (1,795 points)
    Jan 11, 2012 3:28 PM in response to Captiosus77

    It looks very much like a bad case of "white spot" a notorious issue which affected early 15inch aluminium PowerBooks - including mine. Eventually(!) Apple acknowledged the issue and implemented a warranty extension program. This has of course long-since ended and to the best of my knowledge did not (at least in any great numbers) affect the titanium PowerBooks. I mention it only because the cause may be the same as in your case -

    pressure on the LCD from spacers in the display lid behind the LCD. Who knows, maybe the PB you have acquired has spent a long time under a pile of stuff which has put abnormal pressure on the lid?

    Anyway the only solution back in the day was a new display assembly......

  • by Captiosus77,

    Captiosus77 Captiosus77 Jan 11, 2012 4:31 PM in response to Braby
    Level 1 (0 points)
    Jan 11, 2012 4:31 PM in response to Braby

    Braby,

    Thanks for the quick response. It's been so long I had forgotten that issue even existed.

     

    Did a quick Google image search and found two images of the white spot problem:

    Image 1

    Image 2

     

    They are eerily identical to my issue, especially the second image which has the exact same U-shaped spot as mine. I suspect you are likely correct in that it probably was compressed by stuff being stacked on top of it for a prolonged period, especially given that it was at the bottom of the box of the stuff purchased at the sale.

     

    As long as it doesn't ruin the display, it's all good. It may be an old piece of tech but it still runs very well and is a joy to use. With a dark background the issue is less noticable.

     

    Thanks again!

  • by old comm guy,Helpful

    old comm guy old comm guy Jan 11, 2012 5:30 PM in response to Captiosus77
    Level 4 (2,244 points)
    Jan 11, 2012 5:30 PM in response to Captiosus77

    Captiosus77 wrote:

     

    Braby,

    I suspect you are likely correct in that it probably was compressed by stuff being stacked on top of it for a prolonged period, especially given that it was at the bottom of the box of the stuff purchased at the sale.


    I suspect that, too.  That is a 1 GHz Titanium PowerBook and that does appear to be the result of excessive pressure on the LCD film layer.  It may eventually work its way out, though I would guess that is more or less a long shot bet.  It's pretty involved to replace a display module on that machine (a good two-hour project) so if you can live with the artifacts, you still have a serviceable machine.