I've tried everything including swapping battery, LCD assembly, Prox sens(Plugged in and out during start up), BB flex, etc. I've been doing this a long time(22yrs) and thousands of phones, and have not seen this BSOD on a iPhone yet; nevermind the 5s I'm having the problem with now. The PCB below the Flex cover EMI lower two screw holes is fine; no scratching or wear(Totally black). I have a pic, but cannot figure how to upload. There's no liquid damage residue and watermarks are white. Yet another Apple Bomb mystery...