Chosen Solution
Hello, during some testing with a 22.4 Amp hour LiIon battery I accidentally switched negative and positive and now my 3DS won’t turn on even when I’ve connected it to the charger. The DSi had a fuse on the D-Board which you can replace to fix it. Is there a way for the new 3DS?
Most of these machines have both a fuse and protection diode to prevent this from destroying the device. If you are getting no power, first check the fuse. If the fuse is OK or has been replaced, move forward in the circuit looking for a diode that may now be open.
