Ok so the issue you’re having is the Front Facing flex that hosts the Prox sensor and ALS has water damage to the pads underneath the components. You will need to remove both components and apply fresh solder and clean the damaged pads and put the items on a new flex. This is famous for boot looping and dead phones.

So this can be a few things. (1) Your board is a sand which board which has a interposer. Interposer is the middle section of the motherboard that connects the top and bottom together. This model is famous for getting pulled or weak pads on that interposer. With and without pressure will cause the touch to have issues. (2) Make sure that all debris is out of the way on the frame when installing. Also look and see if you see anything that could be applying pressure to the back of the screen when installing. (3) You have crimped the flex cable of the screen and with movement it works or doesn’t work. Try a replacement screen that is known working screen to see if it does the same thing.

Your issue is that your alignment is not perfect. If the dot projector is even off center a little it will throw a message or will scan the face half way and error out. Realign it. May take like 4-5 try’s if you don’t have a lot of practice

I know you don’t want to hear this but this model is famous for needing a CPU Reball. You get solder balls that like to touch underneath the CPU. On the bright side you will only have to get it done once because from experience you don’t get the issue again after getting it done.

Sounds like you likely have a defective charge port.

Likely bearings going out in the fan itself. Likely will need a fan replacement.

Reseat the ram. Make sure Hard drive is inserted. Depending on models it will get picky on certain things

With this console you likely have one of a few issues (1) Needs thermal paste on APU to prevent overheating (2) Failing APU (3) Overheating issue overall

With the Iphone 6s it has a known issue with the wifi IC shorting out internally. It will need a new Wifi IC and have Nand removed and wifi unbinded. Motherboard issue 100%

a few things this could be (1) Defective screen (2) You knocked off a filter around the Display FPC. At this point it will be a motherboard repair needed.