My display sometimes turns partially black or has strange lines

In that case, it would probably be best to at least see how much they're planning on charging me, especially if it turns out not to be the connection and I'd have to go back to them anyway.

Do you think they'd still fix it if I went through their self-service repair store? If I bought an entire display, I wouldn't save that much money, but maybe if I just bought the necessary tools?

I would see lol, but they might just charge you for a full screen even if it is just a connection issue

you could check apple.com/support for a price conformation for a repair to see if it's viable

@southpaw1496 - Sorry, this sounds like the display it’s self is damaged. What happens is the junction of the flex cable to the LCD panel fails. In some cases the displays panel back glass (which is brittle from heavy processing) encounters micro fractures so the metal oxide traces get damaged sometimes the breaks touch reconnecting things.

What sort of usage would cause this damage?

At the beginning of last year, it got an ID card caught in the corner which cracked the screen, which was similar to this, but only the side of the display that had been cracked had the issues.

@southpaw1496 if it is near the display driver chip it may have very well, done what @danj has said.