Won't charge, won't connect to Itunes, but Starts up when plugged in..

This phone has no water damage that i can physically see.

I replaced the charger port 5 times all brand new ports, Nothing worked, I swapped out 3 batteries none worked.

Now the issues is, lets say the phone is dead ok, I plug it into the computer and it says it needs to be charged, now ok the computer charges the phone, the apple logo pops up and everything seems to be ok right? NOPE, As soon as the phone loads up it does NOT connect to Itunes. It discontinues charging, The home button works, The sound works, the mic works but it doesnt charge..

I took working charger ports from other phones i had but nothing is working..

all the pins on the motherboard seem to be fine..

I cant put it into DFU mode.

HELP!!