If your windows phone or Nokia Lumia suddenly blank screen or DEAD, don’t throw away! press Volume Down + Power for 10 seconds. It will revived!
Trust me, Nokia phone isn’t easy to die
I use Nokia Lumia 920 at this example. To lock Nokia lumia network on 3G / 4G only, we can do quick setup by:
1. Go to dial-pad
Type : ##3282 and call
For older version, please type : ##3282#.
Click settings on right-bottom
From this settings, we can set network running on 2G only, 3G only or even 4G only (LTE).
Here is the steps: