i've got one of those and when mine stopped cooling it was the thermo electric plate, also called a peltier, i phoned the manufacturer and they sent me a new thermo electric plate for about £6 i think, but you'll also need some heat sink compound, you can get a small tube cheaply at maplins or similar.
the thermo electric plate is sandwiched between two heat sinks and needs a smear of compound either side.
paul
July 2009