I'd appreciate opinions on the following. Do SI replace the fan or not.
Computer is 2 years old, working fine. What I notice is this. Room temperature is around 68 most mornings when I turn the computer on and boot. Prior to 2 weeks ago, I would only hear the slight sound of air being moved. But since that time, it has been somewhat more noisy for 3-4 minutes when I boot after which it returns to its normal air-moving-only sound. It isn't an alarming noise by any means. I suspect it's sort of like some bearing warms up and expands a fraction from the heat of friction or of the power suipply transformer. So the fan turns with decreased noise and vibration and operates quietly all day.
My question is need I take any corrective faction and if so, what?