Why does my screen go black when the phone is too cold?

FIXED!!! Definitely faulty wiring, I have/had the same issue. I was just pulling my case off to warm up my phone to see it and I ‘pushed' or ‘bent' the top of the phone back (like if you were trying to snap it in half pushing metal side to screen side in the middle and screen side to metal side at the ends) and it suddenly went normal!! No banding no black lower half!! So somewhere in the phone is a loose connecting that gets lost when the metal contacts in the cold. Wondering if other people like me usually remove their case from the bottom……

This is usually due to a very small damage in the screen itself. Usually resulting for from physical damage like a drop.

The screen is usually only sligthly danaged which is why you get this odd behaviour with the temperature changes. Some screens are the opposite and works better in cold when slightly damaged as such.

In most cases a new screen will resolve the problem. Similar issue can happen with any phones with screen damage. In many cases you may just have no image at all from a minor lcd damage so in a way your kinda of lucky that it still had some image.

I think I found a temporary solution for this, of course as you all might know, heating the phone solves the problem temporarily until it cools downs again, but what I learned is that even though it's bottom part that's gone black, the issue is actually with the top of the screen, because that's where all the circuits that connects it to the motherboard are located, so if you heat the top part of the screen, you'll notice that the black part will disappear quickly and will remain that way for a longer period, also, you can use an App called CPU overload, it helps heat up the phone from the inside by running some heavy calculations, and that also helps, try to keep the phone somewhere hot like in the inner pockets of your jacket when it's cold. and yes, I'm using my S7 now to post this answer.

Don't try fix your screen! There is a simple solution.

Go to Settings > About Phone > System information and press Build Number again and again until a prompt for your pin pops up. Scroll down to developer options and turn on ‘Disable Hardware Overlays' under hardware-accelerated rendering. It fixed mine.

In case you tried everything and for some reason you still need to use your S7, alternatives to screen fix:

-Cast your screen to chromecast. You can see the whole screen on your TV.

-Charge your phone during the night, and place it over your router without case. In the morning you screen will work for an hour or so.

-Enable second screen option simulator:

Enable Developer Mode (Settings - About Phone - Click build number many times)

In the screen/video section, enable screen simulator.

You can see a small, real-time second screen and place it where your physical screen still works.

In touch section, you can enable a feature to show where your fingers are in the touchscreen. This also helps.

Having the same issue on my OnePlus 6t. Bottom part of the screen flickers and then goes completely black when outside in the cold.

Anyone know an app that will push the display up to a set point?