I was working fine and then I shut it down and it never turned on again... The led light on the front would turn on and the hard drive would spin then it shuts off it does that over and over... Any one has similar problem??? I have a 13' 2.4 MBP with a 320GB HD (mid 2010) I sent it to apple. it's still under apple care but I don't have the install disks so if it's the HD... I have to buy the disks from apple... What could this be???