Iphone 6 won’t charge…

Hi folks ,

My daughters phone (iphone6 64gb) battery started draining really quickly and then shortly after it wouldn’t accept a charge from any charger/cable.

I ordered a new battery and charge port connector assembly however after replacing these this hasn’t cured anything. The phone will still function perfectly but the battery drains very quick and it will not charge.

What would be the next step or is the logic board fried?

Thanks in advance