This is for Rob who wrote me with a question. Sometimes with the XA series, including XA, XA1, XA2, XA3, etc., there's a lot of electronics stuffed into those little bodies. If the camera is locked up, i.e., won't fire, won't advance the film, shutter isn't working, that's generally an easy fix.
I had one or two however, where the circuit board under the shutter button is broken in two, and the circuit is disrupted. Someone just applied to much force on the shutter button and broke the circuit board.
The XA2, XA3 series has a green light that turns on in the viewfinder when the light is to low for a fast shutter speed. If the green light isn't coming on when pointed at a dark area then there's either a broken circuit board, a loose or unsoldered wire, etc.
You might want to try this, with the bottom plate removed, take a small jeweler's screwdriver and lift a small metal arm which is held down by a very fine spring and gently lift it up and it will close a magnet, you can see the coil and even hear it when the coil closes the circuit. Don't know if that will do any good, but you may want to try it. If you can't find the little arm, let me know and I'll take a digital of it and attach it to this thread.
Good luck!