Try this link:
http://bryantrv.com/docs2/docs/operating/ndr1292.pdf
It may help with troubleshooting. Basically look for the following:
Low battery voltage
AC at the outlet
12v at the junction to the fridge
2 glass fuses on circuit board
There is a hard reset function for this fridge, but I can't remember what it is or where I found it, sorry.
Let us know how you make out.