I have same problem, is it making that familiar fridge noise at all?
If not (like mine) I suspect the thermostat. Just need to find it - bypass it, to see if noise returns ( attach wire bypassing thermostatic switch ), then replace it.
they only cost £12 apparently on ebay.
Probably won't get back on here again - was looking for a solution not the same problem!! but good luck.
And remember - don't kill yourself with electricity!!
There are better ways to go!
Justin, December 2009