Phone screen keeps going on and off

[John Smith228]

I have a LYF phone which has a strange issue. When I switch on the phone and try to open the lock screen - it flickers to the wallpaper, then goes blank and couple of seconds later relocks the screen. And it repeats the cycle over and over again, automatically. Screen turns on, it goes to the app drawer, screen flickers, goes blank and relocks the screen.

Here's the phone in action:

https://www.youtube.com/watch?v=31dr3xIzmXA

Even the top half of the screen which shows network connectivity flickers between showing no sim, then no connectivity, back to no sim. It is also losing battery at a rapid rate because of these changes. It doesn't even charge when the phone is on. Charging while the phone is switched off works fine.

After sometime I was able to login to Play store. But when I try to download an app it just stops after downloading and never installs.