Galaxy S4 half of screen black/yellow

[GalaxiesGalaxy]

Starting about a week ago half of my Galaxy S4 screen was black. I didn't drop it or anything, just woke up and it was like that. Turning my brightness all the way down made the black part flicker and transparent enough to see through. The half black part has now developed a half yellow part as well. The weird thing I found is that when my screen is on for long enough or if I watch a fullscreen video the screen is normal and the black/yellow part goes away. A couple of seconds after I take my phone out of the fullscreen video the screen goes back to half black/yellow.

I don't know what to do. I've tried taking my battery out and holding the power button and I've tried starting my phone in safe mode and it's still half black/yellow. I thought Id post here because I found it bizarre that watching a fullscreen video makes the black/yellow part go away. Any help is much appreciated.

 

[SpookDroid]

Probably hardware failure at this point. Might just be a loose connector or faulty video driver, but most likely your display panel is already damaged. I'd suggest you take it in for repair.

Just to make sure (although I doubt this would help from the way you describe the issue), you can boot up your phone into Safe Mode to prevent any 3rd party apps from loading and see if you have the same display issues. If you don't, consistently, then it's a software issue with an app you installed and you can just find the culprit and uninstall. But if it happens there, then it's pretty certain that it's a hardware problem.