[G2 Q&A, Help & Troubleshooting] Bdev3:
Fixed Dead Row of Screen and also Knock On

I've had the dead row as in the above screenshot for months, just a little higher up on the screen. My knock on/off (dt2w) also had mostly stopped working. I was doing research on a replacement phone (sam g7?, lg g5?, asus zenphone 2?, Moto X), digitizer replcement, etc., after doing research on the various tips and tricks on the Internet and nothing working (did not try opening phone fixes).

I somehow blundered into fixing my phone through the service menu and it's been working fine for over 24 hours now -- knock on now works like a brand new phone and my dead area is completely fixed. Please review the attachments -- I spent about an hour doing various hardware tests, re-installed the touch firmware and rebooted several times, and kept going back to the Finger Paint test to see if there was any progress. I'll list the things I tried and my suspicion is the Proximity Sensor test somehow reset the phone -- I toggled the two buttons several times and waved my hand around until Near and Far displayed appropriately. Note I have been on almost all KK, LP, and MM ROMs, but fixed this from stock rooted Lollipop (30f) on my D800.

1. Starting from Capture 5 image, which is what you first see on D800 entering service mode (3845#*800#), selected Device Test and ran the Service Menu Auto test on Capture 4 (also did manual for good measure).

2. Also from the Capture 5 screen, pressed the Hardware Tests button and focused on the tests circled in Capture 2. The Finger Paint test starts with a black screen, just start moving your finger, and then it shows the dead row. I updated the Firmware a couple of times, and also did the Check Synaptics Touch Panel Test. At first I got a Fail on the first test for the F54 test on the first row, whatever the heck that is, but now it passes (Capture 8).

3. Toggled Knock On/Off Setting various times (Capture 6)

4. Played a lot with the Proximity Sensor test (Capture 3). If I had to guess what actually fixed the phone, it might have been the Enable checkbox. When you toggle it on, wave your hand near the sensor on top of the phone just off left center. The phone screen should flash on and off depending on, well, proximity.

So I don't know what it is exactly that worked, since I randomly tried a bunch of tests for like an hour, but I noticed the Finger Paint test results improving just a bit (one or two lines showing in the row versus none) and then all of a sudden I was good. If someone is more systematic, maybe they can isolate the exact fix. And I hate to say it, but I tried other tests as well and it might have been something I didn't list. But it seems like the hardware is not defective or loose, and perhaps it might have needed the equivalent of a good internal knock on the head from these tests. Like I said, I was about to give up, this problem has plagued me for months and I hope it stays gone. I'll report back if it reappears.

Good luck fixing.

Bernard

3/24 update: Phone worked great for about two days and now the problem is back. I flashed a 5.1.1 ROM and AICP, but not sure if that contributed. On Cloudy G3.3 and the F54 test now fails.