What parts are required for Booting up?

Hey guys, so I bought a DOA nintendo Switch off Ebay for pretty cheap. I’ve already opened it up and tried a new batter also there doesn’t seem to be any water damage also it doesn’t seem to have ever been opened up. Right now I’m stumped as to why it won’t turn on. I figured before I go on a shopping spree and start buying all the spare parts on the internet, I might as well understand what parts are required for the Switch to boot up. Thanks in advance.

If a switch motherboard is fully working, it only needs a battery to boot. Plugging the usb in will trigger it to power on. Or you can also hook up the power button.
You may also want to plug in the lcd and backlight though so you can see it booting.

The chances are however that something is wrong on the board preventing boot, which will require microsoldering work to fix.