I have a DSi that is in very good condition but for the right shoulder button. It does work but I have to press very hard to get it to register. The “lift up the button and blow into it” does actually improve the function of the button for a bit (I use canned air, not moist mouth) but it doesn’t take long at all to NOT work either. Does anyone have a REAL solution that actually works short of disassembly and replacement of the button?
The DSi and XL are arguably the pinnacle of Nintendo’s modern engineering.
The shoulder switches are soldered to a tiny board that’s connected to a ribbon cable, so it’s actually possibly to replace just the switches.
If the ribbon cable is damaged, it’s a tiny and cheap replacement part that doesn’t require even removing the motherboard.
The power board is a discrete child board.
Button presses are handled via metal dome switches. Buttons not working? Pull the dome, clean, then replace with fresh kapton tape.
The only real negative is that two ribbon cables run through the hinge.
The earlier DSes were more of a pain to fix, and the 3DS series started to cheap out by making things harder to access, remove, and put back together.
The XL has zero parts availability. I love them, but you can’t even gert the dual-composite stylus for it anymore.