The best way to fix an Iphone 4S LCD screen and digitizer is to follow the instruction online. The Iphone 4s mobile phone display can easily crack when dropped. To fix the LCD screen you will need precision screwdrivers. Follow the steps below very carefully. I suggest watching the video first before deciding. Note that doing this will definitely affect your warranty for the Iphone with Apple. It is best to seek help of a technician if you think you cannot carry this out.
Order iPhone 4 and iPhone 4S Screens from the link below
iPhone 4 screen replacement
iPhone 4S screen replacement
iPhone 4S White Screen
iPhone 4S Black Screen
Use the above replacement video if the screen on your Iphone 4S is cracked, flickering or broken.