I have the old style CF-50 with 5 LED lights, not digital display. This was awhile back but I think the temperature selection became non-adjustable and the lights would blink erratically.
Thanks I have the 'B' design with the digital display. The display read -18 and the fridge runs but never shuts off and the temp display never changes. So far I changed the board and tested a new thermister with no change.