Replaced Battery, Still not Turning On?

This could be a software issue. If that’s the case, you should probably ask Apple for help…

However, if you are 100% sure that the battery isn’t the problem, there might be some issue with the logicboard. That’s possible to replace, yes but hard. And you would probably lose touch ID features as each individual home button is paired to the logicboard to the phone. And with the fact that this isn’t a physical button and just a sensor, you won’t even get the ability to click your home button unless you go through Apple which will re-pair a new one for around 379$…

These issues are always hard to fix, as I usually tell most people to restore the whole phone, but it seems like that isn’t an option here… I don’t like to say it, but I’m afraid that Apple is the only way here if no genius here might have a great solution.

But if a wipe and a restore is possible, I highly recommend you to hook it up to iTunes and restore the phone.