Mine didn't work either. It also (and still) is "wobbley". I removed the screws from the handle, cleaned the wires and put everything back together and it now works. Check the basics, like do you have 12V
going to the handle when the switch is pushed, etc.
I have not had to get "under the skin" near mine but I'm pretty sure everything is in the handle that could break or stop working.
Worst case is that you do have to get into the wall. You can remove the "trim" around the door with a plastic putty knife (Brett once showd me that it just pops off) and drill out a few rivets near the door to see what's going on in there. There is aluminum behind the luan wood.