this is the part this shows how to fit it. If the other buttons and touch screen are working this may solve the problem and is cheap and easy to do.

Unfortunately, the capacitive touch buttons are part of the front panel display assembly. You would have to replace the entire front panel display assembly. Aside from a hardware issue, it could also be a software issue. Is your phone stock or is it running a custom ROM?

Thanks for the quick replies. Yes i run the stock rom the Touchscreen and the other buttons are working!

I will try to solve it with this replacement.

So the parts finally arrived. I replaced the part and now the screen dont show anything.

At the begining I plugged the phone to power. It showed me the Loading Sign for 2 seconds. Now there isnt nothing on the screen. Did I forget something or did I destroyed something...?