Originally had problem with the refrigerator damper assmbly and disassembled for replacement of assembly as a noise was a result of the plastic rotator being sheered. The digital display showed 4 blinking. Freezer and refrigerator stopped cooling around this time (coincidence?) and removing panels in freezer found fan fine and coils fine. Found that after defrost cycle the coils would not get cold again until I disconnected the power and repowered the appliance. They then got frost on them as was supposed to happen. Any ideas why the defrost cycle is not working properly?

Great News. The damper assembly is replaced and has told the control panel that everything is alright I guess, because everything is now working. Interesting that this problem would shut everything down.