New (to me) Kegerator having issues

I bought this on craigslist http://imgur.com/dbKR3dx was just wondering if anyone else had it. All it says on it is keg meister. If you had it i'm just wondering what temperature setting (1-12) you used? It would help me to get a ballpark so I can dial it in after that. Last night I accidentally froze it so after thawing I put the setting on very low, the cooling plate is still frosting over and covered in ice, could my fridge regulator be broken? Is that normal?

Thanks