Hi Jacob,
If you really want to go deep down the repair rabbit hole, then repair.wiki is the place for you. You'll want to pick up a USB volt/ammeter so you can tell how much power the phone draws, which will help pin down the issue, but go. read this article first.
How To Diagnose & Fix an iPhone 7 That Does Not Charge, Takes 0.006A via USB - Repair Wiki
As far as straight-forward repairs go, you've done the obvious and most likely one already and presumably tried a different charger and cable too. That really only leaves the battery as a possible source of problems before you go down the path of diagnosing board level problems such as replacing the Tristar power controller chip.
So yeah, the next obvious thing to do would be to replace the battery, and after that you're headed in deep.
Good luck and let us know what you find!
crwdns2934105:0crwdne2934105:0
crwdns2934113:0crwdne2934113:0
crwdns2915270:0crwdne2915270:0
crwdns2889612:0crwdne2889612:0
1