Hotpoint Minstral FF 71/FF91 Fridge compartment temp rose to 18C,Freezer ok AT -22C. Removed front and back grills to clear dust blockage, fridge returned to +5. Then started to rise again to +17c. Switched off fridge/freezer to check again for dust but when I switched on again Fan would not work and freezer fell to 0C .what has gone wrong ?Help

Alex, April 2011