FAN gradually comes to stand still after power on..

[wantok]

Hi all,

On power on, CPU fan starts spinning and gradually decreases speed and eventually stops.

What are the possible problems for this scenario?

Thank you for sharing light here.

=:wantok

[urban_s0ulja]

if the computer was put togeather by someone that knew what they were doing and if you are still able to use it without any lockups you'll have nothing to worry about

[KingDeaN]

It's probably just the fan control from the motherboard

If you really want it on all the time you should be able to that feature off in the bios but if it isn't crashing (which it shouldn't be if it is the motherboard fan controller doing it) then I wouldn't bother.

[Philquad]

you better read that again urbs
the fan "stops"

i would be changing fans
if thats not it check bios for smart fan or cool n quiet settings
disable them
dont ever run a cpu without fan going.
= burnout cpu in 10 seconds

what part of "eventually stops" are you guys reading?

[Farmsky]

My guess is a touch of wd40 will do absolute wonders on both sides of the fan bearing. Fan bearings are simple things, and if not lubricated will seize as the temperature rises.

Happens all the time.

[wantok]

2 cases I tried but don't know the explanation why such is happening and what the real problem is.

1. When the ATX12V1 connector is unplugged, the CPU fan spins continuously without problem.
2. When ATX12V1 connector is plugged, the fan spins fast at first then gradually decreases in speed, eventually coming to a halt.

Could this a problem related to;

1. ATX12V1 connector point
2. Fan
3. Power Supply Unit
4. Other than that?

Appreciate all your contributions so far.

=:wantok

[Farmsky]

Fans can be temperature controlled from the motherboard. It is winter

[Philquad]

dont use the 12v, easy
rather fan spin than not spin grasshopper

[RHCP]

dont use the 12v, easy
rather fan spin than not spin grasshopper

If by ATX12V1 he means the 4 pin connector which is connected to the mobo, then i think he should plug it back in.

When does the fan spin down? How long does it take to spin down?
What type of cpu and mobo are you using?

Most cpus wont die immediately if they run without a fan - there's a decent heatsink on most systems, i run my C2D without a fan Even if they did get hot, most modern CPUs will shutdown, reset or begin to 'underclock' themselves if the temperature exceeds a threshold - so as to prevent damage.

When it spins down next time, check the CPU temperature, and then open up a CPU intensive task ie folding @home, or super PI or Prime95 etc run this and watch the temperature and see if the fan starts spinning again.

On an old amd64 system i had an issue where every now and then after a reboot the fan would stop and wont start - only disabling Cool 'n' Quiet fixed it.

Cheers, RHCP.

[virgo]

Wantok,

I have a similar problem to you.

With ATX 12v unplugged CPU and Case fan run but LCD screen says no signal. Using a graphics card not PCI.
Plug ATX 12v in and press on button and both fans start to rotate and stop within 1 second.

The MB is new, the Cpu is new and I have changed the Power Supply.

I have also disconnected the HD and CD. Also removed the memory. Same problem.

Maybe our problems are related and thats why I am posting my problem in your thread.

Any suggestions would be appreciated.