I have a rooted "g'Five President G9(Android 4.2.1)" smartphone. I'm facing a strange problem. If I turn my wifi or bluetooth off and touch anywhere on scree, its display disappears and shows a very dim grey screen. Then until and unless I don't turn my BT/wifi on again, its display won't get back to the normal state(shows a grey screen). When that grey screen appears, I still receive notifications for calls and messages. Even I can respond to calls because I have an estimate about where to touch to answer it. I can also lock/unlock phone thorough that grey screen (which means mobile is not stuck). I have tried restarting phone, but in vain. Please provide some help in this regard.
I can use my phone easily if its wifi/BT is on(but it drains battery with a vigorous pace). I haven't performed any tricks with my device in recent months and I'm facing this problem since last week.
Any help would be appreciated.