Dammit I have had exactly the same issue. Permanent orange light and black screen freezing on HOME when selected instead of powering down. I took the thing apart and messed around with wifi cards and so on to no avail. I held down combinations of buttons and restarted and installed system updates to no avail. I scoured the web for help to no avail - YouTube is full of people making videos either asking for help and demonstrating the same issue, or showing how to take the thing apart and wiggle the WIFI card to fix it. The fact is the unit was dropped (not dramatically, just from child height, while on, on to a carpeted floor) and it behaved like this thereafter, so something is amiss inside.
Ultimately I ended up sending it to Nintendo to be fixed. Defeated.