Mac not booting


macrumors newbie
Original poster
Oct 17, 2014
Hi, I have a mac running mountain lion and when I went to boot it up it's been stuck on the apple logo with the swirling thing. I tried holding Command + r to reinstall but it just restarted the mac when I clicked continue.

I have Boot Camp installed is there anyway to fix the Mac OS from Windows?

also I Booted in verbose and single user mode and they both got stuck at IOThunderboltSwitch I have not thinderbolt devices


macrumors newbie
Oct 20, 2014
2009 MacBook air not booting. Blank screen. Sometimes Apple logo comes up. Nothing happening now. Installed Yosemite.problem ever since I installed. Serial no: W80380FU9A7. Any help would be appreciated!


macrumors P6
Feb 20, 2009
I know it's too late to really help at the moment, but I'd like to present a concept to you:

THIS is why a savvy Mac user ALWAYS has at his/her disposal a SECOND bootable drive.

It can be either a bootable backup created with CarbonCopyCloner or SuperDuper, or a separately-created drive with a copy of the OS on it.

Just connect, and go. This can help you recover from drive hardware/software problems. (Aside, if it's some kind of hardware failure with the Mac itself, it can't "get by" that...)

Again, I know this doesn't help at the moment, but it's something you should consider once you get things together again...