Hotpoint Mistral frost free fridge freezer.

Question

Freezer is working -22C but fridge is rising to +14C. Had bottom vent panel off and cleared large blockage of dust (3 years worth) after which fridge went back to normal +4/5C, FOR JUST TWO DAYS! Am I mssing something. It was switched off, emptied and cleaned when the dust was removed and allowed to stand before starting. Guess it could be the cooling fan inoperative.