black screen on lumia 640xl after latest guild updated

If hard resets didn't help, I think we may need to use the WDRT, although make sure the phone has power.
 
Go to All Settings–>System–>Battery Saver.
Tap on Battery use
Choose Windows Default Lock Screen App to Always Run Background
Hope this helps
 

Members online

Forum statistics

Threads
332,590
Messages
2,255,535
Members
428,709
Latest member
16577