Samsung S4 mini - Android is optimizing app I have Galaxy S4 mini and it showed a message that the Android is optimizing apps, then it hanged at second app, later the phone is not able to boot/Start. Nothing gets displayed on the screen, it just shows a blank black screen. I tried the Volume up + Power + Home button but nothing happened except that the phone vibrated. I need to reset the phone, how do I do it? 
I think the cache/RAM is overloaded.
If want to Hard Reset your phone Keep in mind that you will lost all your Installed Apps, Accounts and Messages.


Power off your phone by holding the Power key or taking the Battery out.
Then press and hold together buttons Volume Up + Home button + Power button, and release this when you see logo Samsung.
Choose using Volume buttons option "wipe data/factory reset", and confirm that using Power key.
Next confirm "yes" previous operation using Volume keys and Power key.
When this operation is completed, select option "reboot".