Rear camera and torch not working

More than likely it is a hardware issue with the board. The 8 plus, from my experience, has a very fragile camera module. I have had to replace a large amount of rear cameras that were also brought to me for a screen replacement. Now, the fact that the torch isn’t working leads me to believe there is a board issue. I don’t micro-solder, so I don’t know what chips would need to be replaced. I have also seen a malfunctioning camera module be the culprit as well. If you know of anyone or have a local repair shop that has a spare rear camera to test, then check to see if it’s as simple as replacing the rear camera. Otherwise, I would find a reputable micro-soldering repair company locally or one like iPad Rehab that you would ship it to.