noisy laptop

[looobylooo]

grrrrrr!
whats causing this sort of electricity buzzing sort of noise please?
its getting on my wick a bit now,
i feel like giving it a quick wack to stop it, like we used to do with the old fashioned tellys, remember when the picture kept rolling?!
the buzzing noise is frequent and lasts for a minute or two at a time, then stops, is nice and quiet for a couple of mins before starting up again.
could it be the fan? because when its about to stop, the buzzing slows down to a fan like whirr sounds, then stops and is quiet again.
the bottom of the laptop isnt hot, infact its cool, and ive got it sitting on a board.
grrrrrrr.. there, its off again..!
its not particularly loud, just flippin irritating, and im ready to give it a damn good wack if it carries on like this! lol.
any ideas please?
thank you :o/

[Answerprancer]

Almost certainly it's the fan, it's probably clogged up with dust - you need to give it a good old blow (if you'll pardon the expression).

[looobylooo]

lol .. right oh ap, i will give it a good one tomorrow then ;o)

mind, i did give it one not so long ago...

[wildwood]

It may be your HDD. Cover the fan grill with your hand for a second and listen if the noise changes.