My MacBook pro turns on the grey screen with the logo comes up, a loading bar shows up, after 5 minutes it loads all and the bar disappears and after ten seconds the screen goes black and the laptop off! Help

See Gray, Blue or White screen at boot, w/spinner/progress bar

OS X Mavericks- If your computer stops or delays while starting up with progress bar

OS X v10.6- Gray progress bar appears under Apple logo during startup

The first link refers to "delays." That sounds like your issue. Does your computer start up this way all the time? If it does then you may have something you are loading at startup that is not compatible. Try removing all Login Items. Also, check Startup Items folders in both the /Library/ folder and the /Home/Library/ folder. Remove anything you find. If that isn't helpful, then create a new admin user account. Disable auto-login if it is enabled. Restart the computer and log into this account. What happens?

My suggestion is this:

If you have a computer in this list or from a more recent date: Computers that can be upgraded to use OS X Internet Recovery.

Install Mavericks, Lion/Mountain Lion Using Internet Recovery

Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.

Boot to the Internet Recovery HD:

Restart the computer and after the chime press and hold down the COMMAND-OPTION- R keys until a globe appears on the screen. Wait patiently - 15-20 minutes - until the Recovery main menu appears.

Partition and Format the hard drive:

1. Select Disk Utility from the main menu and click on the Continue button.
2. After DU loads select your newly installed hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed. Quit DU and return to the main menu.

Reinstall Lion/Mountain Lion. Mavericks: Select Reinstall Lion/Mountain Lion, Mavericks and click on the Install button. Be sure to select the correct drive to use if you have more than one.

Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.

This should restore the version of OS X originally pre-installed on the computer. Now do the Yosemite upgrade.

Thanks so muck Kappy that worked! 🙂

Restart the computer and after the chime press and hold down the COMMAND-OPTION- R keys until a globe appears on the screen. Wait patiently - 15-20 minutes - until the Recovery main menu appears.

Partition and Format the hard drive:

1. Select Disk Utility from the main menu and click on the Continue button.
2. After DU loads select your newly installed hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed. Quit DU and return to the main menu.

Reinstall Lion/Mountain Lion. Mavericks: Select Reinstall Lion/Mountain Lion, Mavericks and click on the Install button. Be sure to select the correct drive to use if you have more than one.

Hi,

I'm having the same issue and I tried to go through your instructions, however when I do, after clicking on the 'Partition' button at the end of the process, it says "Partition failed with the error: Couldn't unmount disk."

What do I do? I don't have the option to do it with any other drives on the left hand screen.

Please help!

Your issue is different. Try starting your own thread where it will receive more attention.

Cheers

Pete

How do you back up files to an external drive?

I tried everything here, but as soon as it looks like it's about to work, my MacBook pro shuts down. I even tried the internal recovery and the same thing happened. I'm not sure if this helps, but when I startup, the screen has a strange pink hue to it. Help?

I Don't know if this will work, but I moved the bar one over on the security options next to erase. After that click erase then move bar back on security options back to original place. It should let you erase after that. I'm currently re installing softwar.

i did this and during reinstalling when it comes to zero seconds remaining, it would start again from 23 minutes, somebody plz help me