i had that, unplugged, removed all the draws, exposed the defrosting pipes which had loads of ice, defrosted them with hairdrier, removed the melting ice blocks, wrapped a coil of exposed copper wire taken from old thick electrical wire around these pipes near the drain plug, put the end of the wire in the drain plug. this is to defrost the hole in the drain plug, i let the wires go down a lot, into the collecting tray at the back.
at the back remove and clean collecting tray.
when all done. dry off with hair dryer, and put back to gether. it has been ok for 5/6 months ever since i di dthis.
tee, March 2011