When I helped a neighbor with his Norcold , the control board was, on the back of the fridge, left side looking through the bottom vent, behind a white plastic cover 4" x 7" . Follow the 110v power cord , that should lead you right to it. Multiple 110 & 12 volt wires to remove before the cover can be removed . Tag all the wires and take a picture before you start pulling wires off. Disconnect 110 power cord , tape up 12v wires.
If memory serves, and some times it does. Fuses can be pulled with needle nose pliers, with the cover in place.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.