How can I diagnose if my LG G2 screen is defective? Until until yesterday, my LG G2 smartphone worked beautifully. All of a sudden, for no apparent reason (no drops or indication of damage), this occurred.


Click for full size image

Clear horizontal and vertical lines appear across the screen. Note how the very top is perfectly fine, and gets worse towards the bottom of the phone.

I am willing to buy a replacement screen an replace the entire part. I have some experience in fixing electronics, and there are lots of nice online tutorials. However, since there was no damage to it whatsoever (it sat on a desk overnight), I began to wonder whether it was the screen at all. 

Is there any method or software to diagnose whether my screen or other parts of my phone are defective, other than buying a new screen and trying it out?
As far as I can tell, the problem is that the LCD is getting interference from the antenna.

To fix it, place some tape in between the white antenna cable and the circuit board. Basically, on the bottom, there are 2 parts that snap on, and then there is another square that is left "floating around". This has to be flat the same orientation as the LCD. Place the tape above it so it insulates it from the white cable that should be passing above it.