Screen Shows Flickering Specs...

Hi, Josh. I have to ask: do you also see these blinking pixels if you're working at your computer and you spin around suddenly in your chair and look behind you?

OK, I didn't really have to ask, but I couldn't resist. It was the "silvery specs around your head" that suggested the question, I think. ;o)

But seriously: if you've read the endless "Horizontal lines in a fritz" megathread in this forum, and you didn't find anything there that either matched the symptoms or suggested a remedy for your seemingly somewhat different problem, I'm not sure what to tell you except that it might be helpful to know a couple of terms that are commonly used to describe LCD display anomalies more precisely. A "dead" pixel is one that stays black at all times; it's turned off. A "stuck" pixel is one that stays the same color at all times: red, green or blue. Either kind of anomaly will show up most prominently against a background that contrasts with it, and very little or not at all against a background that roughly matches it. Are your pixels "dead" or "stuck", or are they constantly or unpredictably changing?

I have no suggestions other than that you read that thread, which I confess I never even try to open any more, since it takes several minutes to load over my cable connection. Perhaps if you are able to describe your problem with greater precision, someone else will recognize it and be able to respond more usefully than I can.

EDIT: One idea, which you may already have tried: you can determine whether the problem is in the video circuitry on your logic board, or in your display and/or its internal cabling, by connecting an external monitor to the Powerbook and seeing whether it exhibits the same misbehavior. If it does, you have a logic board problem. If it looks fine, you have a display or wiring problem. It is almost certainly not a software problem, but of course you could conclusively elminate that as a possible origin by booting to any other volume than your normal startup disk and seeing whether the problem persists.

Josh: Do these pixels actually blink on and off, or change from one color to another, when they ought to be staying the same? If so, they're not "stuck," but malfunctioning in some other way that's less easy to characterize.

"Dead" and "stuck" pixels are defects in the LCD panel itself. Perfection is hard to attain in anything, and nearly all LCDs have a few of these. (Mine has two stuck pixels and one dead one, out of 1,093,120 pixels in all. I seldom notice them.) Every LCD manufacturer and computer display maker has an in-house policy (often unpublished, like Apple's) with respect to how many pixel anomalies, and where located in the display rectangle, it takes to justify a warranty replacement of the unit. If a display doesn't reach that threshold, its owner has to live with the pixels he has.

You may want to download this little freeware utility (it isn't OS X-native but works in Classic mode) and use it to test for dead and stuck pixels in your display. It will enable you to conclusively distinguish those two kinds of anomalies from whatever else may be going on on your Tibook. It doesn't fix anything; it just shows you the anomalies you have. Be sure to read the tiny Read Me file before running the program, or you won't know what to do after you start it.

I encourage you to start the computer up from any bootable CD you have at hand and see whether the display misbehaves the same way while running off the CD. If it does, you've eliminated all software-based causes for the problem.

Not everyone has a spare monitor lying around, but if you do, the external monitor test I described above would help to narrow your problem down further.

Well, that is a puzzle. I can't think of much else to suggest, other than this: if the problem occurs only in certain applications, pick the one in which it seems to be worst, and trash and reinstall that application from scratch. Be sure to trash its preference file(s) along with the application. Does the newly-installed copy also have the problem?

My second and last idea, especially if the misbehavior occurs in all applications, is that it may be caused or exacerbated by heat. Does it begin as soon as your Powerbook is turned on, after being shut down long enough for its innards to cool down to room temperature, or does the problem appear only after the PB has been running for a while? Does it happen before your cooling fans come on, or afterward, or both at different times? Is your Powerbook situated on a flat, hard surface where air can circulate easily all around it, to optimize cooling efficiency?

if at all possible i would recommend that you take the powerbook to an Apple Store where you can demonstrate the symptoms in person since trying to describe them over the internet seems to be a problem and could send you in the wrong direction altogether. good luck.