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View Full Version : Roaring fan at power-up

crazynightowl
02-15-2006, 03:07 AM
When we turn on the power to one of our PCs a fan begins running at a very high speed (and making a substantial noise) for about a minute or so and then slows down to normal speed for the rest of the time we are using it. I have completely cleaned everything and all seems in good order. The machine has been in use for about 2 years with no problems but has just recently started this strange behavior.

Since the system is cool when we start it I don't think it's heat related.

Any ideas?
jcnoernberg
02-15-2006, 09:38 AM
My computers have always done that. The fans get full power on bootup until the bios/fan controller gets going and tells the fans there is no heat and to slow down.
beerbelly
02-15-2006, 10:50 PM
The machine has been in use for about 2 years with no problems but has just recently started this strange behavior.
While I agree with jcnoernberg that a system with any fan control tecnology will perform somewhat erradically at start-up, I am bothered by the fact that the problem has recently started.
It can be anything, but I suspect a fan going bad.
saphalline
02-15-2006, 11:00 PM
This is one of those weird issues. It could be a BIOS setting or a sign to replace the PSU.
beerbelly
02-15-2006, 11:20 PM
OOPS!
Sorry crazynightowl, forgot to WELCOME you to the forums.
crazynightowl
02-15-2006, 11:55 PM
Thanks very much for the 'welcome' and for the other thoughts and ideas. I did notice this same problem on another machine just recently (only did this one time but I happened to be there when it happened) and it looks now like the PS was going bad on that machine at the time so maybe there is a connection. Makes me wonder if the PS might be going wildly out of regulation for a short peroid and producing abnormally high voltages which run the fans so fast. These supplies are often cross-regulated and a fault on one output could throw off the regulation on other outputs I suppose. That could be a real disaster!

Maybe I'll spring for another supply and see what happens. I'll report back if it does turn out to be the real problem.

Thanks to all,

crazynightowl