recently fixed magnet at rear on flap motor,after resetting the fridge freezer it stays on for approx 6hrs-yesterday 9hrs but then stops working and starts to defrost. today left it for several hrs to see if it would come on but NO,so i took the rear panel out and at the top left corner near the flap there is a foil patch and this was very warm any ideas please, HELP

aeb, May 2014