Display goes white

Hi, i making a weather station and near all works.
Im Working with an Arduino Due and an ITDB02-5.0.

But if i’m using the Touch screen the Display Display draws line or goes white but the sketch is still running. It happens primarly when i power it over my switching power supply, when i use it per USB it happens rare.

circuit: http://prntscr.com/dh7jxz

A picture and the sketch are as Attachment

Wetterstation.ino (35.8 KB)