Cool-See 821-2049-A With Bracket HDD Hard Drvie Cable For 13" MacBook A1278 2012;

Something wrong happaned to your macbook laptop, it seems look like:
(1)froze suddenly
(2)Internal hard drive disk not recognized, not respond any more
(3)freezes takes long to start up
(4)flashing folder icon on boot
(5)got the flashing question mark folder, a sure sign of death when the computer turned back on
(6)didn't boot up properly and the screen displayed a folder with a question mark! Restarting again did not make the folder with question mark go away
(7)boot to a gray screen or keep freezing when it did boot.
(8)A new drive did not solve the problem.
(Some one get a methord bellow to get if his own drive is broken if you are fortunate enough to have another Mac at home, I would purchase a USB to SATA adapter, and use the Disk Utility on the other Mac to make sure the hard drive is still good. Once you've done that, start the computer using the second DVD that your MacBook Pro came with (if you still have it) and hold D as it starts, then run the hardware test to rule out a bad logic board. After all this, then you should take it to the Apple Store to confirm&