Chosen Solution
So this 6s plus is just dead. Had water damage, removed all shorts, board started smoking, shorted vccmain to ground, fixed that. Vccmain on diode mode says 803, no short. But ppgpu and ppcpu show a very low reading like 008 or even 003. Is this thing beyond fixing? Vccmain is normal, I had to take the audio codec off since it was shorted. Would that prevented it from being recognized by iTunes? It also generates no heat at all, anywhere.
The logic board is shorted out and I recommend you replace the entire phone.
