Posting again to provide more information! When I disassembled the device the other day, the device turned on and refreshed the screen several times, but was not able to charge. It powered on once when I was removing the speaker connectors, and randomly when I was manipulating the device after that while plugged in. Here are some pictures too:
The board:
https://i.imgur.com/1tnWN5e.jpg
The screen after I got it to refresh:
https://imgur.com/a/ZRVgRJh
I've been charging it for about 48 hours now with no change. Also tried leaving it for 24h without a battery, with no change.