Tell me more ×
Ask Different is a question and answer site for power users of Apple hardware and software. It's 100% free, no registration required.
up vote 0 down vote favorite

I have a 2009 white MacBook that doesn't seem to be waking from sleep properly. I close the lid at night to put it in sleep mode, and when I open it the next day, the display backlight doesn't turn on – I just get a black screen.

I know the computer itself is powered on because I can hear the fans running, and I know it's not in sleep mode because the sleep indicator light turns off when I open the lid. It's exactly as if you lowered the brightness to 0.

I tried adjusting the brightness, hitting all sorts of keys, etc. and nothing gets the display to come back – so I've resorted to holding the power key to force it off, then booting it back up.

Is there anything I can do, or is this a hardware failure? Surprised as the machine is only 3 years old (though it's my employer's, not mine!).

UPDATE: I have an external monitor hooked up to the MacBook, and when the MacBook's display fails to turn back on after waking from sleep, the external monitor also doesn't display anything – just the default "no signal" message that appears when the monitor is on but not plugged into a computer.

If this were an issue with the MacBook's internal display cable (as it seemed like it was), would that also prevent the external monitor from displaying anything?

share|improve this question
Can you post a picture of the display at an angle without any glare when this happens? – duci9y Dec 11 '12 at 16:05
I had a similar issue when I plugged an externally powered USB hub into my laptop (2007 MBP). The backlight went out and wouldn't come on until a full power cycle. Unlikely to be the exact same issue, but if you have anything plugged in (USB/firewire/etc), take it out and test without that, in case its a high/low voltage on wake-up, from any peripherals. – drfrogsplat Dec 12 '12 at 0:05
I recommend resetting SMC. The display backlight is controlled in part by this chip: support.apple.com/kb/ht3964. – bispymusic Mar 12 at 20:07
In response to your UPDATE question... A loose display cable should not prevent an external display from working. In fact, I have seen users do this intentionally to older iMacs with bad displays. – bispymusic Mar 12 at 20:08

2 Answers

up vote 0 down vote

I have the same problem and have found that if you repeatedly hit the ESC button, eventually the backlight will turn on.

share|improve this answer
up vote 0 down vote

This sounds like a hardware problem, if using the brightness keys on the keyboard have no effect.

Have you tried resetting PRAM? (Hold down Command-Option-P-R while rebooting) This is the first thing that Apple will have you do if you bring it to them.

One suggestion, if you get the backlight on, don't close the lid, put the computer to sleep using the shutdown dialog box, and see if that helps. If it does, then it is probably a bad video cable.

share|improve this answer
Interesting – I tried sleeping the computer last night from the Apple menu (instead of shutting the lid) and when I woke it this morning, the display turned on just fine. It's possible the wire is bad; I think this computer was dropped at one point before it was given to me (there's a crack in the case to the left of the trackpad). – daGUY Dec 12 '12 at 15:25
The laptops owned by corporations usually get much more abuse than ones owned privately. There is a ribbon cable that runs through the hinge and connects the screen to the motherboard, so a drop can easily damage this cable. Is there a camera in the lid? If so try using it to see if it works properly. That same cable would have to carry the signals for the camera, audio, and light sensor. – Mark Thalman Dec 12 '12 at 16:30
Yes, the camera works fine (I actually just used it today, coincidentally). – daGUY Dec 12 '12 at 17:19

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.