Chosen Solution
my sound is broken! Volume switch has a broken piece missing and the 2DS does not play any sound. It’s muted but I can’t turn it up.
ussferight we would need to see more of what this looks like. Sometimes you can bridge the volume control since it is only a potentiometer, or you can try to replace it with a new one. It does require some soldering. So remove the motherboard and lets fix it. Looks like you can get the volume control from places like this Adding images to an existing question - iFixit Repair Guide