Kitchen Aid repair question

[aalk]

Our expensive Kitchen Aid side by side refrigerator hiccuped today. Don’t know why. Everything was working fine this morning, but later in the afternoon, the display was out. The light works inside, the ice dispenser is providing ice and the water tap is working. The fan doesn’t appear to be cycling nor does the compressor. In looking at the schematics, it looks like it could be one or both of the control boards, but have limited resources to define the problem. Can anyone give me an idea as to where or what to look at? I am thinking that there might be a problem with the relays, but that is only a guess. Thanks in advance.