I had fan rattle in my first 24" alu imac (something I was more than used to with my old Windows box) that I bought in Dec, should have known as the corner of the box was crumpled. Anyway I took it back and after demanding a replacement.
It's now silent until about 3 a.m. when hush, the babies are sleeping, the farmers, the fishers, the tradesmen and pensioners, cobbler, schoolteacher, postman and publican, the undertaker and the fancy woman, drunkard, dressmaker, preacher, policeman, the webfoot cocklewomen and the tidy wives. Young girls lie bedded soft or glide in their dreams, with rings and trousseaux, bridesmaided by glow-worms down the aisles of the organplaying wood. The boys are dreaming wicked or of the bucking ranches of the night and the jollyrogered sea. And the anthracite statues of the horses sleep in the fields, and the cows in the byres, and the dogs in the wet-nosed yards; and the cats nap in the slant corners or lope sly, streaking and needling, on the one cloud of the roofs.
You can hear the dew falling, and the hushed town breathing.
Only your eyes are unclosed to see the black and folded town fast, and slow, asleep.
At that time I can just about hear my iMac's fans.