You can download the Atwood HE2 refrigerator service manual here. While not written for the "RV owner" it does contain some very good "theory of operation" and troubleshooting information. You can download it here:
https://bryantrv.com/docs2/docs/atwoodreefer.pdf
This link is to a more detailed document, and also contains parts information. Both together should provide most of the information you need:
http://techsupport.pdxrvwholesale.co...0801-Rev-4.pdf