[NPMUG] Powerbook G4 12 inch - screen gone black

[Victoria Bush]

The screen on my Powerbook G4 has gone black.  The laptop boots up (I  
can hear it) but the screen cannot be seen unless a bright light is  
on in the room and then it is still extremely dark.

This happened out of the blue last night on the way home from a  
trip.  It worked fine yesterday morning prior to leaving the hotel.   
During the drive home I took it out of its case to play some games  
during the 5 hour car trip and I couldn't see anything at all.  We  
were driving after dark.

When I returned home I found I could vaguely see the screen if I was  
in a brightly-lit room.  I have gone to display and the brightness is  
turned all the way up.  It seems to make no difference if I slide the  
control all the way down or all the way up.  The monitor light keys  
have no effect either.

I found the following information at applefritter.com but I am afraid  
to do ANYTHING until I hear from this board.

Powerbook G4 screen goes black randomly...
Submitted by bigd on March 9, 2007 - 3:08am. Hardware Repair Help

I have a 12" Powerbook G4 1.5" and lately the screen randomly turns  
itself off, the whole thing goes black, like it was asleep or off,  
but the computer keeps running just fine. The computer itself stays  
running. What I've been doing is putting the computer to sleep by  
closing the lid, letting it rest for a few seconds and turning it  
back on by opening it.

I can still see that the screen is on, but the display is dark. It  
randomly does it. I switched the power settings to "never" for sleep  
and like 5 minutes for display sleep. That worked as long as its  
plugged into the AC adapter. When I unplugged it it did the same  
thing. I closed the lid and then it went to sleep and then I opened  
it and switched the battery settings to the above, and it was fine.

I set the PMU and NVRAM again. So far it's not doing it but I am  
worried that it's a backlight issue or something else? I have heard  
of random sleeping problems with the powerbooks, but mine doesn't  
actually go to sleep. Any insight would be great. Thanks!

bigd


that's more of a power manager thing
Submitted by coius on March 9, 2007 - 3:19am.

the power manager controls sleep as well as the brightness of the  
display. Sadly, i never found out what the solution was on my old  
iBook before I sent it in to get it replaced by my current G4 iBook  
(i had the 900Mhz G3, They gave me a 1.2Ghz iBook after my G3 went in  
14x Undecided ) anyways, it sounds like the power manager is having  
problems.

I would say if it looks like it's still doing, what you do, is unplug  
the machine, pull the battery (save your data first before shutdown!)  
and press the CUDA switch (probably under the keyboard if it has one  
or something) and reset it is fully. If you have time, and can wait,  
let the system sit for 24hrs w/o power whatsoever.
It might be that the power manager did not fully reset itself if the  
LCD Backlight goes off again in the future.

if it still has warranty, and it continues to do it, call apple and  
let them know, it might be a hardware problem (most likely not, Apple  
just would rather replace mine that have me send it in for the 15th  
time)

Anyway, Good Luck!
Coius


HELP!

Victoria Bush




-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://davesevick.com/pipermail/npmug/attachments/20081006/066acee5/attachment.htm