Hello,
I have a particular case with my Nintendo Switch:
It started draining battery power visibly for no reason. So I naively replaced the battery, but that didn’t fix the problem.
I analyzed the board with a thermal imaging camera, and the only area I see heating is the BQ battery management component when the console is plugged in, but I think that’s normal (approximately 50°C).
I replaced this component as well as the M92, with no better results.
I noticed that the console wasn’t charging properly. It starts fine at about 13W, but then drops to around 2-3W when the battery is only at 30%…
I admit I don’t know where to look anymore…
If anyone has any ideas, I’m all ears 
Thanks in advance.
Jonathan