Chosen Solution
I have tried to do the following: Replace the front camera flex with an original one, use an original screen and even original home button. I tried booting up the phone without the camera flex connected I’ve tried to restart through ITunes both normally and DFU mode It keeps getting stuck at the apple logo and won’t go past. Any suggestions?
This is not the kind of problem that can be remotely determined. You clearly have a logic board issue based on the tests you conducted. The only way to understand what the problem is would be to directly probe the board. This will require someone with micro-soldering skills to troubleshoot. You have done pretty much all you can at this point. Did anything happen to the phone prior to this issue?
