Chosen Solution

I replaced the battery in my wife’s phone 2 weeks ago. Once replaced there was nothing wrong with the screen and it was now good as new. I looked at her phone yesterday and see this:

The screen below the dark spot is also dimmer than the rest of the screen going all of the way to the bottom. You can kind of see it in the picture but it’s much more noticeable in person. She said she didn’t drop it. What’s wrong and what do I need to repair it?

Usually it’s either two of these things, the screen cables need to be replugged or the screen has gone faulty. Rarely it’s the backlight circuit on the board going partially faulty on one side.