Hi guys, can any of you reccommend a place that can do diagnose on an iphone? Got a second hand iPhone 11 pro recently and want to check whether the screen and camera are original parts. Battery and Display shows 'Unknown Part' but shop explained it by saying it's been replaced with original parts but different serial number?

Also I've been testing the camera the last few days but it seems to have problem focusing and the photos are a bit 'warmer' than what I've seen on review sites. I also have an iPhone 8 which I've been comparing it to and most times the 8 takes better photos! The focusing problem is especially apparent in the front camera. Attached is a sample taken at arms length. Left is iPhone 11 pro, right is iPhone 8. First is full scale, second pic is zoomed in.