ibook g4 dim display

emikbre

I have a 12" ibook g4 purchased in August, 2005. I cracked my LCD a few months ago and purchased another online, and replaced it. It worked perfectly for about a week before the backlight went out.



I did some research and thought it might be a bad inverter board. I replaced that, and it didn't do a thing. I have reset all the PRAM, etc etc. on the computer. The brightness has absolutely no effect on the screen, and even when turned all the way down, the screen does not go black as it should.



I think it might be a bad inverter cable, but before I take it apart, or take it to be fixed, does anyone have any suggestions? It would really help me out. I am currently using a lamp behind the LCD to see what I am typing.



Thanks.

karelia

Quote:

Originally Posted by emikbre


I have a 12" ibook g4 purchased in August, 2005. I cracked my LCD a few months ago and purchased another online, and replaced it. It worked perfectly for about a week before the backlight went out.



I did some research and thought it might be a bad inverter board. I replaced that, and it didn't do a thing. I have reset all the PRAM, etc etc. on the computer. The brightness has absolutely no effect on the screen, and even when turned all the way down, the screen does not go black as it should.



I think it might be a bad inverter cable, but before I take it apart, or take it to be fixed, does anyone have any suggestions? It would really help me out. I am currently using a lamp behind the LCD to see what I am typing.



Thanks.

So you've got no backlight, but the ghost image of a display is there? If you've already replaced the inverter, either you have a bad reed-switch/inverter cable unit, which I would NOT recommend replacing yourself, or you've got a bad LCD.

apallo

I've worked on quite a few of these with exactly the same problem, and 9 times out of 10, the culprit is the logic board. From what i can tell, the circuitry that supplies power to the LCD burns out, making it seem like a blown backlight.



p.s.

You can test the reed switch by running a magnet over the right edge of the top of the case.

pawn3d

Quote:

Originally Posted by Apallo


I've worked on quite a few of these with exactly the same problem, and 9 times out of 10, the culprit is the logic board. From what i can tell, the circuitry that supplies power to the LCD burns out, making it seem like a blown backlight.



p.s.

You can test the reed switch by running a magnet over the right edge of the top of the case.

what does that do?

cowasaki

Quote:

Originally Posted by pawn3d


what does that do?

It detects whether the lid is closed