I dropped my phone and the screen cracked however instantly the touch screen stopped working.

[WPCentral Question]

The screen is only cracked in the corner which is why I thought i would still be able to use my phone but the touch screen wont work at all. This has never happened to a touch screen phone I have owned before why has this happened?

 

[jmshub]

You could try rebooting your phone and see if you fixed it, but you may have cracked the digitizer in the exactly wrong spot. It could have been the corner where the wires connect to the digitizer that has broken the circuit. You're likely looking at needing to replace your touchscreen.

 

[Harrie-S]

On the touch screen a flex foil makes the contact to the motherboard. In your case you have probably bad luck because the corner where the crack is is also were the flex foil is.
Bing a picture of a touch screen than you can also see the flex foil.

 

[KarmaEcrivain94]

Same thing happened to me. It sucks :/