MacBook Pro can't see the HDD
Several days ago my mid 12, 13.3-inch MacBook Pro 2.5GHz Dual-core Intel i5 with Mountain Lion 10.8.5 refused to follow any commands. To restart it I holded the on/off button for some seconds and it switched off. Then I switched it on, but it showed me the Language-choosing bar, and then OS X Utilites. I choose disk utility but it is unable to verify or repair the disk. Seems like MacBook can't see any disk in it. What's wrong? Is it possible to get the files from the disk? The disk is Samsung 500GB SSM8F 655-1786B *DL6325504R6F6C1AT*
MacBook Pro (13-inch Mid 2012), OS X Mountain Lion (10.8.5)