Nintendo switch works with good battery no charge

Hi guys new to this forum and trying to learn.
I have a switch which doesn’t power in I have place a known good charged battery in and it powers and works but no charge icon when plugged in.

I can’t seem to find schematics for it.

I’ve tested for shorts around BQ and MT and no shorts are detected.

Any help in diagnosing this and helping me learn would be greatly appreciated.
Thank you

As I don’t know what else you have checked I would start at the basics, how does the usb port look? Is the fuse still good?