Hacking Bircked 3ds (part 2 if you didn't know)

[needhelp3ds]

so, as i said quite a while ago, my bro's new 3ds ( not xl ) just says immediately on startup: "an error has occurred. Hold down the power button to turn off the power, then turn it on and try again."
When I press L + R +A + Up then power, it sorta turns on, but doesnt go to the update screen.
I have tried things. Help

 

[Joom]

I had this happen when the wireless card became loose. Try disassembling it and make sure it's connected properly.

 

[needhelp3ds]

I had this happen when the wireless card became loose. Try disassembling it and make sure it's connected properly.

k ill try

--------------------- MERGED ---------------------------

I had this happen when the wireless card became loose. Try disassembling it and make sure it's connected properly.

where is the card

 

[Joom]

Under the battery. You'll have to disassemble the bottom part of the console.
https://www.ifixit.com/Teardown/Nintendo+3DS+XL+2015+Teardown/36346

I know this is for an XL but it's essentially the same.