I've got an older fridge that I use for my kegs. It keeps the beer at about 49F. It's just not cold enough for some of the styles I've put in there. I've defrosted the unit for two days, I've turned the freezer compartment all the way up (coldest setting), the fridge compartment all the way up (coldest setting), and I'm still not getting anywhere. All of the ice cubes in the freezer are frozen, so I know the fridge is capable of getting colder. I'm led to believe that killswitch to the compresser is in the fridge and it trips when it hits about 49F. I actually drilled some holes from the freezer to the fridge to see if it would get colder. Alas... What's my next step?