Okay Jeff, when I read your post this morning.. I was eager to get up and find that
"access hole", because I remembered there is a small (9mm) plastic hole cap in
the center of the thermostat & vent panel!
Got in there and popped the cap.. Yeah, needed my screwdriver..
It clicked and clicked as I turned CW, then went into defrost mode..
I'm leaving it run for 15 min, to see what happens..
Then I'll advance it back to compressor run..
Edit:
The defrost cycle started normally, but the ticking sounds soon stopped..
No water was heard gurgling down into the pan..
Now, it seemed to be working like before.. So we pulled out the fridge and checked the lower pan for water..
No water.. So, maybe the drain tube is frozen over too.?.