Loud buzzing noise on my computer

[Almendros]

Hi, when I start my computer there is a hum for maybe 10 secs then I get a loud buzzing noise like angry bees. after about a min. this goes back to the quiet hum. I have 3 fans and all the holding screws are tight so I am sure it is not them, anyway why dont they vibrate from the start?
Are there other moving parts on a computer? It happens not always but perhaps 18 times out of 20 and I have had it happen if it has been on for an hour then it goes away. Thanks for any ideas ........Almendros

[Whickerman]

sounds indeed like a fan's on its way out. It's very little to do with the fixing screws, the bearings are shot. Get a replacement from PC World for about a tenner. BUT - there are several sizes, might be best to bring along your old one. Oh, and if the new fan is thicker then you need new fixing screws too, but you should be able to replace it easily enough for an exact copy.

BTW - in the slim possibility that it's not your fan (you should check with the cover off, you can slow/stop a fan (but only for a second!) to check ) it could be either a cd drive has worked loose (tighten all screws) , or a harddrive heading for the hills. If it's the latter, back up your files now!

[Almendros]

Thanks very much Mr Whickerman, you have given me a few things to check out