Check your flash memory (eMMC) chip. Revise fw revision and check blocks.

The check dont write and is safe. If your device freeze you memory is damaged. For unfreeze the device remove battery and restart.

(Brickbug) Usefull with any version of:
- Samsung Galaxy R.
- Samsung Galaxy SII.
- Samsung Galaxy Note.
- Samsung Galaxy Nexus.
- Samsung Epic 4G Touch.

(Sudden Death) Usefull with any version of:
- Samsung Galaxy SIII.
- Samsung Galaxy Note II.

However the use of this application is your responsibility.

Information about brickbug:
- http://forum.xda-developers.com/showthread.php?t=1644364

Information about Sudden Death:
- http://forum.xda-developers.com/showthread.php?t=1993044