How did you notice a problem?
Was it just no longer cool inside? Did it start making any strange noises? Any problems with the display?
Just wondering because a few months back mine stopped working for a little while. By that I mean it wasn't cooling, the display wouldn't come on completely, just flicker "00" very fast and the unit was also making a strange beeping noise whenever plugged in. Vinotemp tech support suggested it might be the control board (but they weren't sure) they asked me to take the back panel off and snap a picture so they could check their inventory.
When I pulled the wine cooler away from the wall and removed the panel for the picture, I started checking everything I could think of to see if there was a loose connection somewhere.
Turns out simply opening and shutting the door forcefully a few times solved the problem and its been fine ever since.
I'm curious to see what symptoms your unit has and I just wanted to piggy back my story here incase anyone has a similar problem with their unit.