So I have a macbook pro updated with mavericks. Today for some reason, it entered in this boot loop and I can't get it off. I've tried safe mode, however as soon as the loading bar appears, it shutdowns and bootloop starts all over again. Tried enter into "Command+S", but same thing, doesnt give me enough time to type and shutsdown. I tried turn on using option, and selecting the recovery option, however boot loop again. I made a bootable usb with mavericks, but when I try to open the disk utilities it shows me nothing, just the apple logo and the loading wheel. What else can I do ?