Why do I get an error after booting up my 2DS?

Hi, I repaired a 2DS that wouldn't turn on. Now it turns on, but after a few seconds I get an error and that I should turn of the console and restart.

I've tried finding a solution on the internet, but I couldn't find a solution that worked for me. The wifi board is a microchip soldered on to the pcb and I don't have any cartridge plugged in either.

I'm at a loss.