Your HTC Desire 820's screen is broken ? Or your touchscreen doesn't work anymore ? Here is how to repair it !
You can buy the whole LCD + digitizer (it's how the touch screen is called) for 30$ if you are patient and order from China.
The operation is fairly complicated and long, if you are not experimented with repairing phones, please do not try this.
I am not responsible of any damaged caused on your phone.
This operation cost me about 1h, because I didn't know how it was built inside, so I was pretty careful and everything went well.
You'll need a basic phone repair kit (look the picture) with a Torx 5, a few spudgers...
Step 1: Changing the Screen
Good luck, watch the whole video and if you have any questions please ask !
Please be careful, do never apply force if you are not sure of what's under or you'll break something !