I had this problem with my Sony Xperia T2 Ultra. Have yet to figure out what it is...
When I tried to diagnose my phone, I replaced the new "faulty" screen with a new one but the same thing happened.
The DIGITIZER seems to be working because when I swiped up when I though the boot reached the home screen, I could feel the phone vibrating because I was pressing the different keys to my passcode.
-
So in my case it seems to be the display cable that's the issue, but at this point it's that or the logic board.
+
So in my case it seems to be the display cable that's the issue, but at this point it's that or the logic board. So check for any tears in the display cable or scratches on the logic board. That's the most I can offer now from my own experiences
I hope you understood what I meant in the digitizer paragraph.
I had this problem with my Sony Xperia T2 Ultra. Have yet to figure out what it is...
+
+
When I tried to diagnose my phone, I replaced the new "faulty" screen with a new one but the same thing happened.
+
+
The DIGITIZER seems to be working because when I swiped up when I though the boot reached the home screen, I could feel the phone vibrating because I was pressing the different keys to my passcode.
+
+
So in my case it seems to be the display cable that's the issue, but at this point it's that or the logic board.
+
+
I hope you understood what I meant in the digitizer paragraph.