0

Score

Avatar
David Jackman
1

Asked

LCD Backlight turns off after booting through grey screen

History

I have a MacBook Pro 15" that I just had the hard drive go bad. I put the new drive in and booted from the install DVD. After the computer boots passed the grey apple screen the backlight turns off. I can see the install menus and successfully reinstalled Leopard without the backlight. Is there a light sensor or lid sensor that may be missing or misaligned after replacing the hard drive that could explain why the backlight turns off? I have closed the lid, put the machine in sleep, attached an external monitor. The backlight doesn't flicker so I really feel like this is something easy I may have overlooked. I have replaced lcd's in laptops before as well as hard drives in MacBooks without this issue.

Edited by: oldturkey03 ( ) , iRobot ( ) , machead3 ( )

Tried SMC and PRAM resets ?

lemerise,

Is it a sleep issue? Is the HD still spinning? Does touching keys or track pad have any effect?

machead3,

http://www.youtube.com/watch?v=i79zxpXZ5... This is the youtube link. The screen turns off around the 3 minute mark and I shine a flashlight through the back so you can see the language menu so it is running.

David Jackman,

Post Answer

1

Score

Avatar
machead3
68.9k

Answered

Accepted Answer

PermalinkHistory

It could be RAM

Try reseating or switching your RAM.

If this answer is acceptable please return and mark it.

Good Luck,

N

I've tried the SMC and PRAM resets I believe. Isn't that just removing the battery and pressing the power button for 10-15 seconds? Also I don't believe it is a sleep issue as it is a new hard drive and as soon as the Mac boots to the language selection screen the backlight turns off. I'm uploading a video to youtube to show an example and will post the link as soon as possible. If I take a flashlight and shine it through the apple logo I can see the language selection and I can move the mouse to select things.

David Jackman,

1

Score

Avatar
Sam Amick
13

Answered

PermalinkHistory

If this is the same problem I just solved, if you were to plug in an external monitor it would boot to that even though the lid open when you power up the system.

Reason: it thinks the lid is closed. This was due to corrosion on the motherboard interface for the small circuitboard that detects the magnet on the left side of the LCD assembly when the lid is closed. The circuitboard also interfaces with the battery connector and is connected to it with a wiring harness.

You can leave the screws for the battery connector in place but you must remove the keyboard/touchpad assembly then remove the 4 screws that hold the metal bracket in place that sets against the ports that run up the left side of the motherboard. Then you can back the circuitboard out from the motherboard, scrub corrosion off the connector holes on the motherboard and the interface pins on the small circuitboard, plug it back in and you should be good to go!

Happy times.

0

Score

Avatar
Kevin Salas
1

Answered

PermalinkHistory

This is the power inverter, it's pretty cheap on ebay but if you don't know how to change it yourself get a tech to do it. cost me 13 bucks on ebay.

Add Your Answer

View Statistics:

Today: 0

This Week: 3

This Month: 8

All Time: 3,004