PB G4 display is Pink after sleep

Question

Hello
suddenly my powerbook g4 titanium screen has a pink haze over it when 1st wakes from sleep. seems to be getting worse quick. i havnt seen this since my 1st crt monitor way back in '93.
any thoughts?
replies to this message will be emailed to me.
Thanks
wayne

Answer 1

The pink seems to be a product of the aging of the fluorescent backlight tube, which is located at the bottom of the display. As it gets older, the backlight tube is slower and slower to reach full brightness and normal color temperature after it's been off. Eventually, in at least some cases, it loses the ability altogether. A screensaver doesn't turn the backlight off, so it doesn't bring on the problem. Sleep turns off the backlight, so the problem does appear after sleep, or after any event that dims the backlight considerably for more than a few seconds.
To verify this, dim your screen with the F1 key until only one brightness increment is showing at the lower end of the scale. Leave it that way for a minute or two, then bring the brightness rapidly up to full with the F2 key. If you've been seeing pink after sleep, you'll see pink when doing this.
I don't know whether backlight aging is accelerated by always using the display at full brightness or ******** by using it at a lower setting whenever possible, but it wouldn't surprise me to learn that there's a relationship there.
Powerbook display assemblies are glued together — for the sake of greater rigidity, I presume — and are not meant to be disassembled. This makes replacing the backlight tube or any other component inside the display bezel very difficult: difficult enough so that when anything goes bad inside, Apple replaces the whole display instead. It is possible to dismantle the display and replace individual components, then glue it back together again, but the process is so labor-intensive (see one man's well-documented procedure here), and carries such a high risk of causing at least cosmetic damage, that I suspect few professional service departments will undertake it — and it won't be cheap in any case.
If you have nothing to lose, a source of good used display parts or whole displays you can cannibalize, and plenty of time, you can try replacing your own backlight. But be aware that you'll have to disassemble your Powerbook completely. Most of that is child's play compared to separating the display casing parts, but any way you look at it it's a big, complex job.