Powerbook G4 Screen Backlight Broken

[dotobi]

Hey

My Powerbook G4 Screen Backlight has broken. I can see that the screen itself is working (just!) as everything is still displayed on it but it's just REALLY REALLY dark and unusable. I've checked that the brightness is on full. Also hooked an external monitor up to it and that is fine. So it seems the backlight is broken.

Is this something I can fix. Is there anything I can check?

Thanks

Kev

 

[SYQUEST]

Depending on your technical abilities and adeptness, replacing the display is VERY involved. If you check out this link: macs.about.com , scroll down and look for PB G4s, and click on the link, you should get a list of "How Tos" for the PB. Go select one, and see if that is something you want to do, or take it to an authorized Apple service place or the Apple Genius Bar.

I just downloaded a bunch of them for the G3 iBook, since I have to replace the HDD in mine. The PDFs have color pictures and are very detailed! They even give a list of needed tools. This is not something for the faint of heart to do.

Hope this helps!

....JIM....

 

[xavdeq]

I have a similar problem. PowerBook G4 1GHz, Titanium

I have analyzed what happens and come to the following description:

1- phenomena A:
the backlight LED works, the cabling seems OK

the backlight turns on when starting the computer but gets swiched off after a few seconds, each time.
(it started with swiching off now and then)

2- phenomena B:
Normally, when pulling down the display, while in use, the backlight is swich off and the computer goes to sleep,
when opening the laptop, the computer wakes up and the blacklight is turned on.
question: what makes the process?
I could not find any physical switch that is activated when pulling up and down the display. The backligh is turned on/Off before when the display is a little above the keyboard (no physical contact)

3_ It suggests the following questions
Is there a sort of sensor that detects the screen coming close to the keyboad?

Is there a software controll that turns ON/off the display?

Is there an uncontrolled process that switches the backlight off?

thanks for any hints

Xavier

 

[xavdeq]

I recall after some research.
Some answer might be here:

http://www.lcdparts.net/howto/FAQ.aspx

Any comment?
Xavier

 

[SYQUEST]

To answer your question about the "opening and closing" of the laptop in relation to the display turning on/off, there is a reed switch in the edge of the display frame that is activated/deactivated by a small magnet in the top cover near the keyboard when it comes in proximity of it. The reed switch is connected to circuitry on the mother board.

I have not verified for sure, but I believe the "backlight" of the display IS part of the display and if it is not working properly then the display won't be working properly either, and would need to be replaced.

....JIM....

 

[kamilien1]

I am having phenomena A happen on my g4 15". Any known solutions to this? I think i'll have to take apart the laptop and first check for connections. I read from a few other places that there is a temperature dependancy sometimes, so I will see if this solves the problem. However, if neither of these two guys work, anybody know what part I would need, or how to test which part to get?