MacBook Pro 15" Unibody Troubleshooting
- MacBook Pro Unibody won't turn on
- Laptop shuts off when I unplug it
- Flashing question mark on startup
- Laptop restarts unexpectedly, or does not properly display picture
- My machine boots, but the display remains dark
- Other problems
The 15" MacBook Pro Unibody replaces the original 15" MacBook Pro, with a new design centered around a case milled from a single brick of aluminum. Troubleshooting is fairly straightforward.
Note: This troubleshooting guide covers all Unibody 15" MacBook Pros. The original MacBook Pro 15" will be covered on a separate troubleshooting guide.
MacBook Pro Unibody won't turn on ¶
Your computer will not boot.
RAM issues ¶
If your computer beeps three times, there is a RAM issue. Either you have insufficient RAM to boot, or the RAM you do have is faulty. First, access the RAM slots and ensure you have RAM installed. If you have two chips, first reseat them and try again. If that doesn't work, try one chip at a time to see if one of the chips prevents the machine from booting. We offer replacement RAM to replace faulty chips. If none of the above methods work, you may have a bad logic board.
Bad power adapter ¶
If your battery is not charged, is completely dead or is removed from your machine, please make sure you are NOT using a 60W MacBook Magsafe adapter! A MacBook Pro is shipped from the factory with a 85W adapter and needs the full 85W to boot. The 60W adapter will keep a charged battery from draining but does not have enough juice to provide full charging functionality. If your power adapter is bad, the computer will run off a battery, but it won't charge. If your battery's charge is too low, it will be difficult to diagnose a bad power adapter. The easiest way to test this is to borrow either a battery or power adapter to test in your machine. If you have the same problem with a fully charged battery, you most likely need a new logic board.
Thermal Sensor Issues ¶
If the fans run at high RPMs, but the computer does not boot, there is probably an issue with the thermal sensors.
Late 2008/Early 2009 models feature a thermal sensor on the heat sink. First, ensure that the thermal sensor on the heat sink is plugged into the logic board. If it is, try replacing the heat sink. If this does not fix the problem, the logic board most likely needs to be replaced.
Mid 2009 models house thermal sensors on the logic board. Therefore, in this instance, the logic board may need to be replaced.
Bad logic board ¶
Also, 9 beeps on startup indicates a logic board problem. Try contacting your nearest Apple representative to determine if they will fix this problem (be sure to back up your data first!). If not, you must replace the logic board yourself.
Laptop shuts off when I unplug it ¶
As soon as you unplug the computer from a power source, it shuts off
Dead battery ¶
If your battery is dead, the computer will run fine off the power adapter, but will turn off when unplugged. A dead battery can manifest itself in many forms: It may not accept a charge (this particular symptom may also indicate a problem with the logic board), the computer may not recognize the battery, or the battery may be recognized as charged but fail to power your computer when the AC adapter is unplugged. We sell batteries for Late 2008/Early 2009 and Mid 2009 models.
Flashing question mark on startup ¶
The computer displays the flashing question mark when it can't find a bootable operating system. This could be because your OS is corrupt, the computer doesn't have enough RAM, or your hard drive is failing.
Bad operating system ¶
Try booting off an OS CD. Run Apple's Disk Utility and try to repair the disk. If this fails, reinstall your operating system. If you can, erase the hard drive prior to reinstalling the OS.
Not enough RAM ¶
This is quite rare. If you have insufficient RAM for your computer to boot the operating system, you may get the flashing question mark. Installing more RAM or downgrading to an older operating system will fix this. OS X 10.5 requires 512 MB RAM, and OS X 10.6 requires 1 GB RAM.
Bad hard drive ¶
The hard drive may have been erased, corrupted, or damaged. If the hard drive has been erased, format it as HFS+ and reinstall your operating system back onto it. If it is corrupted or damaged, you need to replace it. Failing hard drives can display intermittent data corruption prior to failing completely. They often gradually get louder and start to click. If your hard drive is making abnormal clicking noises but still works, back up your data immediately and replace the hard drive. Any of our 9.5mm SATA hard drives will work in your computer.
Laptop restarts unexpectedly, or does not properly display picture ¶
Your laptop restarts repeatedly or unexpectedly, the screen looks distorted or scrambled, or the display remains blank when powered on.
Failed graphics processor (GPU) ¶
Certain MacBook Pro models going back to 2011 have been known to develop problems with the dedicated AMD graphics chip, and may be eligible for free repair through Apple. A permanent fix requires reballing/replacing the GPU or replacing the entire logic board. However, simply disabling the GPU will allow your laptop to successfully boot using the (less powerful) integrated Intel graphics processor:
- Boot the faulty MacBook Pro in Target Disk Mode by holding down the 'T' key at startup.
- Connect it to another Mac.
- From the working Mac, navigate to System/Library/Extensions on the laptop.
- Find any files that start with AMD and move them to another folder.
- Navigate to System/Library/Caches/com.apple.kext.caches and delete it, if present.
- Eject the Target Disk Mode MacBook Pro, power off, and then reboot.
This is a temporary fix, but should allow your machine to boot successfully. To make this change permanent so that your laptop always boots using the integrated graphics processor, see the instructions at this link.
My machine boots, but the display remains dark ¶
Symptoms of this are a dark screen, but everything else seems to be running.
If your screen isn't working but you can successfully use an external display, the built-in display may have failed. We sell replacements for Late 2008/Early 2009 and Mid 2009 models. If this still doesn't solve your problem, you may need a logic board repair or replacement.
Other problems ¶
If you lose firewire or ethernet, the only thing to blame is the logic board. Because there are many components of the logic board, many possible symptoms indicate logic board failure. Any one of these components can fail and leave the others intact. Loss of USB also requires the replacement of the logic board. If you lose the use of another component of your computer, such as the display, battery, or even power, and replacing the apparently non-working part didn't fix the problem, it is possible that the logic board may need to be replaced (see above).