Chosen Solution
Just replaced my wife’s iPhone 6 screen with one from iFixit and it has vertical gray lines. I tried reseating the cables. No dice. Tried unplugging battery for 30 seconds. Checked connectors for bent pins. Don’t see any.
This is normally because of a pinch in the ribbon cable that has damaged data lines or the LCD cable was flexed at the LCD and broke connections. I have also seen this in rare occasions if the digitizer cable is not properly seated.
Either the above answer by chriswku03, or it’s because the units enclosure is bent out of shape. It is a pretty thin piece of aluminum after all, so it doesn’t take a whole lot before its bent, especially if dropped.
I plugged in the original cracked one and it worked fine. iFixit sent me a new unit that works perfectly. Great customer service!
