iPhone 4 not starting

I have seen this happen 3 times now.

iPhone stops working suddenly - it just goes dead and whatever you do, you cannot boot up. Tried following:

  1. Long pressing lock button (on top). 
  2. Use special screwdriver and remove the screws near speaker and blow.
  3. Try to connect to your MAC/Windows and see if it gets recognized in itunes/drive. 

None of the above worked. Simple solution to fix is:

Press Lock & Home Button together for 10 to 15 secs. Apple icon should come up :-)