Hope this helps and you can recover your data! Do that, and if/when it works, then plug into the other Mac and immediately copy off all of your most important files, followed by your less important files, since the drive could fail again at any time. When hard drives start to fail, occasionally you'll be able to reboot several times and they'll work again. This boots into Firewire/Thunderbolt Target Disk Mode, which basically turns your laptop into an expensive external hard drive. If you have another Mac and a thunderbolt (or firewire if this is an old mac) cable, you can try repeatedly rebooting while holding down the While they've got it apart, they can put in a new drive (I'd recommend an SSD upgrade if you have a spinning disk currently, since it'll speed your machine WAY up). Unless you have experience taking apart Macbooks, and have the appropriate drive sled to offload data from your (possibly) failing drive, I'd highly recommend taking it into a Mac service place so that they can copy the data off your drive before it completely fails (if it hasn't already). This assumes you have previously used your account to downloaded the installer at some point. Window to find the installer you want to download again. In doing so you'll have to log into your Apple ID account (under the Store menu) on the Mac App Store and go to the If you haven't actually got an installer, you can use the Mac App Store to redownload it. Now run the the OS X Installer from the other MacBook to install OS X on the MacBook Pro Run Disk Utility to erase the MacBook Pro's hard drive so that it's formatted in Mac OS Extended format. The MacBook Pro's hard drive will appear just like an external disk to the other Macbook. Key down until you see an icon floating around the screen. Startup your MacBook Pro while pressing the Reconnect the hard drive inside the MacBook Pro.Ĭonnect the two MacBooks via Firewire cable. If not I'm hoping you can get access to either or both of these from your University's tech support.Īssuming you can proceed, follow these steps: You have access to a suitable Firewire cable Since you have access to another MacBook and since it appears your USB thumb drive with OS X 10.11.5 on it isn't a bootable disk, I suggest you startup your MacBook Pro in Target Disk Mode and install OS X using the other MacBook. In addition, your troubleshooting was partly in error because you shouldn't have formatted the drive in exFAT format if you intend to install OS X on it.

Mac startup with question mark