Samsung Galaxy S4 i9505 Switches off When pressure applied to motherboard

[AC Question]

My Samsung Galaxy S4 i9505 switches off immediately, when pressure is applied to motherboard, for example if i put in the four screws on the top of mid frame it immediately switches off. I have a piece of paper under motherboard to stop it cutting out, this works, but if i put in top 4 screws on mid frame it will not start? Can anyone explain it please.

 

[Spagman72]

Have you had any work done to your phone?

If so... Soldering can cause shorts and make the phone turn off.