> So what I learned is that dark areas are receiving too much juice, or > perhaps in the case of our mono TFT edge-darkening, where the liquid > crystals are _more_sensitive_ . . . Boy ain't it great to be so ignorant, > it leaves me with so much still to learn! <G> > > Not a mono TFT PB500, but close enough . . . I've got a _good_ Duo 250 > TFT display I'm going to try on my 2300, which with a previous 280 TFT > screen had done the darkening corner thing. If the 250 screen now > suddenly exhibits darkening corners, it'd be a good bet that something on > the LB is to blame, rather than the display itself. > > Dan K > > From: "Kai Steinmann" <[EMAIL PROTECTED]> > > That's somehow what I think, too. As I said - I'd doesn't seem to be a real > display problem but rather a problem with some other hardware parts of the > Powerbook. But which? > By the way: I've shut down the Powerbook overnight and it tourned out that > just like the b/w display my new color display seems to recreate after a > longer time switched off. But the colored (red/green/blue) horizontal lines > will become more and more very quickly - only minutes after switching on the > PB again. > Well, I believe that if it's a harware problem somewhere on the board I'll > have no chance to get rid of that. :( > > > Looking forward to your results > Kai
A hardware problem with the stuff that drives the display will almost always cause geometrically regular defects, things like blocks or stripes that go dark/light. A power problem will affect the entire display more or less uniformly (the PB100 seems to have a problem with the -21V LCD panel bias, causing the entire display to blank out, intermittently at first, then more or less permanently after that). The gradual and nonuniform diffuse darkening that Kai's photo shows is something else. I think that some months (maybe a year) ago, someone on this list offered his theory that there might be some contamination that poisons the liquid crystal material. If bad seals are to blame, then it would make sense that the problem would first show up near the edges. Since Kai notices this darkening even with the backlight off, that theory might looks stronger. Or, maybe it's still thermally related; the LCD goo might still be getting cooked by the circuitry on the panel itself, if there happen to be warm/hot chips located near the edges. Not having any LCDs to look at right now, this is just noise. If anyone on this list happens to live near Stanford University and would be willing to donate an LCD that exhibits this weirdness, I'd love to take a look at it. And Kai, if you happen to live anywhere near Stuttgart, it so happens that I'll be in Ludwigsburg in a few weeks... --Cheers (und herzliche Grüße), Tom -- Prof. Thomas H. Lee Center for Integrated Systems, CIS-205 420 Via Palou Mall Stanford University Stanford, CA 94305-4070 http://www-smirc.stanford.edu 650-725-3709 ph, -3383 fax -- PowerBooks is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! | Support Low End Mac <http://lowendmac.com/lists/support.html> PowerBooks list info: <http://lowendmac.com/lists/powerbooks.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/powerbooks%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
