i have been using toshiba refrigerator GR-32H32KT for several. Recently i have cooling problems. both the freezer and the frig compartments are only partially cool. if i raise the thermostat switch ice forms in the ducts and blocks air passage. Previously it was running quite well on 1 or 1.5 on thermostat switch. Now the cooling is less. The meat and fishes do not freeze well. Please advise. Thank you. Soe