re: iPhone 7 wont seem to charge or power on

In an apple store, apple doesn’t replace the logic board, if the phone is that far gone they can replace it with what’s called a service replacement which is a brand new iPhone, straight from the factory with no accessories or let you decide if you want to upgrade to a new phone. Service replacement iPhone 7 should cost around $319 and has a 90 day warranty, a newly purchased phone has a year warranty and can have AppleCare added additionally.