(SOLVED) (SOLUTION) The cause of this problem is the SIM CARD!!!!!
Just remove your current sim card then restart the phone and connect to WIFI. Observe for about 10-15 mins nothing blacking out, flickering like an old light bulb or constantly fading like when you turn off an old TV screen. Then try inserting another sim card to phone. Observe again for a couple of minutes after rebooting.
To confirm if it is the existing SIM card that caused the problem, insert back that original SIM then reboot.
BOOM! it flickers, then fades slowly to black then blacks out so even knocking on the screen won't turn on the display you have to press the power button 2x to open the unlock screen.
This happened to me last week and I observed it using different scenarios (eg. turning off wifi, turning off data, turning off face detection then on my first day I removed my sim card and put another sim card on G3 then i was happy the problem was gone.
But since I need the original sim I put it back to G3 after a day then the problem came back.
Now I am not using my original sim and I am using my replacement sim and it didn't show any signs of the problems.
Just remove your current sim card then restart the phone and connect to WIFI. Observe for about 10-15 mins nothing blacking out, flickering like an old light bulb or constantly fading like when you turn off an old TV screen. Then try inserting another sim card to phone. Observe again for a couple of minutes after rebooting.
To confirm if it is the existing SIM card that caused the problem, insert back that original SIM then reboot.
BOOM! it flickers, then fades slowly to black then blacks out so even knocking on the screen won't turn on the display you have to press the power button 2x to open the unlock screen.
This happened to me last week and I observed it using different scenarios (eg. turning off wifi, turning off data, turning off face detection then on my first day I removed my sim card and put another sim card on G3 then i was happy the problem was gone.
But since I need the original sim I put it back to G3 after a day then the problem came back.
Now I am not using my original sim and I am using my replacement sim and it didn't show any signs of the problems.