iPhone 7 USB not detecting after U2 Replacment

Hi I have had an iphone 7 that was stuck on connect to itunes after u2 ic being damaged when customer tried to charge his open on a bus and power surge killed his phone. After replacing the U2 IC phone has started to work fine now but when connected to the charger it does not charge and does not draw in any current. Does the iphone 7 has Q2 sort of ic for USB like iphone 5,5s? may be they need bypassing. I have replaced the U2 ic twice now and still no luck with charging. Any help will be appreciated