MacBook display backlight doesn’t turn on after waking from sleep

backlightdisplaymacbook prosleep-wake

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?

Best Answer

Make sure you are using the laptop with the correct model magsafe charger - if you use a different model's charger, eg a 15 inch 85 watt charger or such, it can cause this problem to occur. A reset of the PRAM would normally cure the problem temporarily.