My rear facing cameras and flash had suddenly stopped working one day. After troubleshooting I found that it was most likely a hardware issue and not a software issue.
The repair guide on iFixit was extremely simple to follow and I was able to follow it smoothly up to a certain point. The tri-point Y000 head that came with the kit did not seem to fit perfectly into the screws and I ended up stripping 2 of the 4 screws holding the display and battery shroud to the phone, and 1 of the 3 screws holding the shroud covering the front camera and rear camera ribbon cables' attachment points to the logic board. This meant that I was unable to separate the display assembly from the main body of the phone which further complicated the repair process. Luckily I was able to swivel the top plate out of the way just enough to get access to the ribbon cables attaching the rear cameras to the phone. The down side to all this is that now I will most likely never be able to make repairs to the phone again thanks to the screws being stripped. To make matters worse, having the screen still attached meant that I was also unable to apply a new layer of water-resistant adhesive to the inside border thus essentially making my iPhone 7 plus an iPhone 6 plus.
If it's your first time repairing like this was for me, BE CAREFUL not to strip your screws. I'm sure this is just a rookie mistake on my part, but be extra careful with how much force you put into unscrewing these delicate points.