| Author |
Topic |
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68kman
Starting Member
USA
15 Posts |
 Posted - 10 Jul 2002 : 13:29:16
I have a powerbook 170 and It works ok but after it has been on for a while the corners of the LCD screen become dark. But when I turn it off for a while it goes away. What could it be? interconnect board
interconnect board screen cable
motherboard
LCD screen Need speed?!!!
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G4from128k
Full Member
USA
873 Posts |
Posted - 10 Jul 2002 : 13:36:18
Do the corners get progessively darker with the margin between dark and normal creeping in from all four courners? If so, I would suspect the backlight. Problems with the digital magic or wiring would tend to affect more than just the corners (tending to affect rows or columns or colors).G4From128k by Day: Mild-Mannered Engineer and Trapeze(tm) Artist
by Night: Colonel of Truth, Justice, and the Macintosh Way
Reserve Officer in 68kMLA Cantankerous Coot Contingent
& User of the Hockey Puck Mouse of Radial Symmetry |
68kman
Starting Member
USA
15 Posts |
Posted - 10 Jul 2002 : 13:47:17
I don't think it's the backlight. The corners of the LCD screen become dark from black pixels that form when the computer is on for about 15 to 20 min.
The Back light looks bright.
Need speed?!!!
Get an Apple II !
Watch the text fly!!
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G4from128k
Full Member
USA
873 Posts |
Posted - 10 Jul 2002 : 14:19:44
Hmmmmmmmmm... When you say "black pixels", do you mean that you can see a given pixel in the corner turn black, while the next pixel over stays bright white? Once black, does the pixel stay black until you turn of the machine and let it rest or does it flicker? And do all four corners darken evenly?G4From128k by Day: Mild-Mannered Engineer and Trapeze(tm) Artist
by Night: Colonel of Truth, Justice, and the Macintosh Way
Reserve Officer in 68kMLA Cantankerous Coot Contingent
& User of the Hockey Puck Mouse of Radial Symmetry |
68kman
Starting Member
USA
15 Posts |
Posted - 10 Jul 2002 : 14:57:44
The corners slowly turn black. First the edge of the screen slowly turn dark in the corner. Then it spreads out a bit. If you leave the laptop on, the pixels get so dark that it becomes black.Then bottom left corner has the worst case of it and the top left corner is not as bad. The top right corner does it a little bit. Then the bottom right corner does not show any darkened pixels at all. Thanks for helping me. Need speed?!!!
Get an Apple II !
Watch the text fly!! |
G4from128k
Full Member
USA
873 Posts |
Posted - 10 Jul 2002 : 15:30:17
quote:
Thanks for helping me.
Your welcome, but so far, I feel like all I've done is ask questions. I get the impression that the effect is not a white-black thing, right? That corner pixels tend to darken progressively and that pixels closer to the corner darken more and sooner than pixels a little further from the corner? Does adjusting the brightness change the effect? (I guess I'm still not convinced that the problem is not the backlight -- that the output of the thing is fading in the corners) Anyone else have experience with aging PB backlights? G4From128k by Day: Mild-Mannered Engineer and Trapeze(tm) Artist
by Night: Colonel of Truth, Justice, and the Macintosh Way
Reserve Officer in 68kMLA Cantankerous Coot Contingent
& User of the Hockey Puck Mouse of Radial Symmetry |
68kman
Starting Member
USA
15 Posts |
Posted - 10 Jul 2002 : 17:09:06
Adjusting the brightness does not change the effect at all.
Does this mean I have to replace the LCD?
Need speed?!!!
Get an Apple II !
Watch the text fly!!
|
maclover5
LC Doctor/Hot Rodder
Australia
5830 Posts |
Posted - 11 Jul 2002 : 05:53:22
I have seen this before on a PowerBook 180.The PowerBook 180 uses the same type of B&W active matrix screen as your 170, and it was exhibiting the same problem as your 170. I tried adjusting the backlight, and all the obvious steps, and i believe the only way you can fix it is to replace the LCD. I'm not sure exactly what does it, although i'm thinking that in the corners someone or something has probably pushed on the screen hard. As you know, LCD screens do funny effects when you press on them, and if you press too hard, this can damage the display. This is what someone could have done before you got the 170. Hope this helps -------------------------- Pizzabox LCs RULE!!!!!!! Warrior maclover5
68k Macintosh Liberation Army
Number of 68ks Liberated: 6
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Trash80toG-4
NIGHT STALKER
USA
2899 Posts |
Posted - 11 Jul 2002 : 06:43:42
quote:
I have seen this before on a PowerBook 180.
my "parts" 190 for the MacAntFarm hack came with a broken LCD, you can't believe what fun it is to squoosh the liquid around in a broken (but not leaking) LCD. your explanation sounds plausible, i didn't realize they were REALLY all THAT liquid!  jt  ™.
Trash Hauler: call sign: eight-ball
C.O. AC-130H SpecOps 68kMLAAF |
Powerbook 170 screen problems
68k of the Week: kastegir's PowerBook 180.