hello, 

I have a inspiron 7520 se and sometimes when i restart my computer i think i hear my hard drive ticking and then i get a message saying: No boot device found. 

also sometimes when my computer awakes from sleep mode it doesn't respond anymore and when i reboot it i get the same message as above.

i have tried this: http://en.community.dell.com/support-forums/laptop/f/3518/t/19518551.aspx sometimes it works sometimes it doesn't.