written by: Finn Orfano•edited by: Michael Dougherty•updated: 1/25/2011
It’s every MacBook owner’s nightmare: you press the power button only to find your MacBook won’t boot up. While the stuff of nightmares, It’s important to know what to do if your MacBook won’t boot up. We look at some basic troubleshooting that can help restore your MacBook when it won't boot up.
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Whether it’s an older MacBook or a cutting edge unibody MacBook Pro, Apple recommends the same troubleshooting steps for all Mac owners. For this article’s purposes we will be troubleshooting an Apple laptop that seems to be completely dead meaning that there is no video output on the screen and the power button seems to have no effect at all.
1. Is the battery plugged in and the MagSafe adaptor on? This question may seem redundant, but double checking that everything is plugged in correctly and in working order (including the power socket you’re plugged into) is the first step in the process. You can confirm that the MagSafe adaptor is providing power to your MacBook or MacBook Pro by checking for a green or red light. If the light isn’t on, try another outlet or unplug the MagSafe adaptor for one minute and plug it back in. The light should turn on.
2. If your MacBook or MacBook Pro still won’t boot up, you should unplug any USB devices and other peripherals. If you’ve recently installed any user-replaceable parts like RAM or a hard drive you should double check that the new parts are compatible and fully functioning. You can do this by quickly swapping them out for the old parts. If the MacBook or MacBook Pro boot up with the old parts but not the new ones, then the new parts may be defective or incompatible.
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3. The third option is to reset the PRAM (Parameter Random Access Memory) and NVRAM (Non-volatile Random Access Memory). These two types of RAM are comparable to a PC’s CMOS, meaning that you will lose some very basic system settings – don’t worry, your files will be safe. Reset the PRAM and NVRAM by pressing the power button and immediately holding down Command-Option-P-R. You should hear the start up chime followed by a second identical chime. More detailed instructions on resetting the PRAM and NVRAM are available at the Apple web site.
4. If resetting the PRAM and NVRAM has not brought your MacBook or MacBook Pro back to life there’s one final thing to try before sending it off to Apple: resetting the SMC (Systems Management Controller). In order to do this, remove the battery from your Mac (if removable) and unplug the MagSafe adaptor. Finally, press and hold the power button for five seconds or the power button and left shift key for 5 seconds on the MacBook Air. Reconnect the MagSafe adaptor and reinstall the battery and press the power button. You should be greeted by the familiar Apple chime. A more detailed guide is also available at the Apple web site.
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Contacting Apple Care
If none of these four troubleshooting attempts have succeeded then it’s time to hand off the Mac to Apple. If you’re covered by Apple Care simply contact the Apple Care and explain that your MacBook or MacBook Pro won’t boot up and what you’ve done to troubleshoot the problem.