We recently had a customer who needed a back glass iPhone 4 screen repair because his was scratched up. How it got scratched is because he used a buffer to clean it up. Yeah, that is correct, a buffer like you use to clean your car. Apparently the iPhone 4 back glass does not pass the buffer test though (no we don’t have video to prove it).
When we replaced it with a back glass, the customer notified us that there was slight discoloration so we replaced that as well. Upon further review, we’ve noticed a bunch of the back glass we see has slight discoloration in some spots, although this is noticed under a light in a ‘where’s Waldo’ type of eye game.
So to review, don’t buffer the back glass of your iPhone 4. Also, you may have to deal with slight discoloration for the back glass of you iPhone 4. If this bothers you we can provide an iPhone repair with back glass that is not discolored.