Yosemite stuck on 50% boot

[Webcrawler2090]

Hey guys,

Got a mid 2009 Macbook pro Yosemite

Been working perfectly fine, all of a sudden the Mac gets to 50% boot then restarts. I've tried cmd + r just hangs on 50%

Safe mode, just loops back round to the loading screen

I've lost the cd so at a loss what to do

 

[simonsi]

Try cmd-option-r to get the recovery options.

 

[Webcrawler2090]

Thanks do i do this after the bong? And hold until I see apple logo?

 

[simonsi]

Sorry it is cmd-r you want

http://support.apple.com/en-us/HT4718

If it isnt completing then you may have a disk failing/failed.

You may need to try making a bootable usb stick with the installer file to reinstall, you will need the installer file, Diskmaker X and another mac to make it on.