This is exactly what happened when my Twist took a swan dive with a quadruple half-gainer onto a concrete floor. With the guidance of the above video (thank you Steeljan!), I was able to get it apart to have a gander at the board. Turns out that the wires attached to the left (battery end) of the circuit board had pulled loose.
Edit: The whole assembly is just press-fit into the battery compartment. Some padded (with masking tape) pliers and a bit of wiggling was all it took to get it apart.
All I had to do was follow this simple process to get it working again:
1) Ransack my workshop looking for my iron and solder for a good 30 minutes.
2) Spend half an hour trying to get the wires to stay put long enough for me to solder them back on (after verrrry carefully stripping them a little more).
3) Cuss up a storm when I burnt my hand on the iron and dropped the Twist back onto the concrete floor and broke the wire to the top connection (on the right, in the vid).
4) Spend another 10 minutes fussing with that wire until I managed to solder it back on, and:
5) Spend another 10 minutes trying to get the button and board back in the hole properly so that it wasn't jammed.
Bing bang boom. Easy as pie.
Twist works just as well as it ever did, though.
Edit the seconde: Some steps are, of course, optional.