2DS xl i need pressure, but why?

Today I bought a 2DS XL, but the LED only lights up briefly and it doesn’t turn on. However, when I apply some pressure near the X/Y buttons, it starts up just fine. But shortly after I release it, it turns off again or freezes.

I’ve already opened up the DS once, but I couldn’t identify anything. Even after reassembling it, the same problem persists.

Sounds like bad joints on the board. Open it up and see where the pressure correlates on the board, Identify the component there, make sure there is no liquid/corrosion etc if no then you could attempt a reflow and see if that resolves your issue

No corrosion but the liquid idicator is a bit pink.
And im not that good with this stuff that i could reflow

here are some pictures (the pictures are from the internet, but i marked the spot)

i checked everything there but i found no problem

sadly i can post pictures here

No corrosion but the liquid idicator is a bit pink. just looked it up, that normal, that means to liquid damage

Yeah, pretty typical these indicators go off even with just high humidity/mild liquid ingress. If you can provide high quality photos of the board front and back I can take a look, you can post your images to an image sharing site - for example animagesharingsite (dot) com

I’m guessing though based on your description that this is a joint issue which can likely only be resolved with a reflow at a minimum or a reball etc if not

Do you have a hot air station?