CPU fan acting flaky

[Ryland]

When I swapped my PSU over to a PC Power and Cooling 750 I just got I starting having multiple issues with my computer, one of which was my CPU fan not starting right. I reinstalled my old Antec PSU and all of the problems went away except for the CPU fan. This is on the machine in my sig and the fan is the stock Intel retail fan.


What it is doing at boot (or on reboot):
The fan will start spinning slowly, stop and the motherboard will beep (this gets repeated 1-3 times)
then the fan starts spinning quickly and all is good.

The fan doesn't make any noise so I doubt it is out of balance and I have used compressed air on it but that didn't help. Is this more likely a motherboard issue (the new PSU fried something) or a dying fan?

 

[aigomorla]

its called a pwm fan. (normal)

and its normal.

it will spin as there is work done on the cpu and how fast it spins is determined by how much work the cpu is also doing.

Originally posted by: Ryland
What it is doing at boot (or on reboot):
The fan will start spinning slowly, stop and the motherboard will beep (this gets repeated 1-3 times)
then the fan starts spinning quickly and all is good.

so wait you have bootup issues?

 

[PCTC2]

I've had multiple boards take a few spins to get the CPU fan up and going. It's fine.

 

[Ryland]

After upgrading the PSU when I boot I get the "cpu fan not running" error beep for a few seconds until the fan is fully able to kick on. This never used to happen, when I would hit the power button the pc would power up, all fans kick on and all would be good (no extraneous beeping involved). I am going to try to figure out whether it is the fan or the motherboard that has the issue by swapping the CPU and SysFan2 cables because SysFan2 starts at full upon boot.

Edit: I just realized that the CPU fan cable is 4 wires and the standard system fan is 3 wires. I can't run that test.

Edit2: Hmm..someone else mentions that the board has 2 PWM headers. I will have to try it in the other.

 

[Ryland]

Originally posted by: PCTC2
I've had multiple boards take a few spins to get the CPU fan up and going. It's fine.

It never used to complain before I upgraded the PSU. Now it does. I guess I really shouldn't care since it does start and my motherboard has thermal protection for the CPU in case the fan does crash.

 

[zagood]

Disable any smartfan settings in BIOS. If that works out, set the smartfan settings so the fan min. rpm is 50%.

edit: is this stock or aftermarket heatsink/fan?

-z

 

[Ryland]

This is the stock HSF.

 

[Ryland]

Originally posted by: zagood
Disable any smartfan settings in BIOS. If that works out, set the smartfan settings so the fan min. rpm is 50%.

edit: is this stock or aftermarket heatsink/fan?

-z

I did that and this morning it did not beep when started.

 

[zagood]

Sweet. So it's just a fan alarm.

Now that you're sure, you can enable your previous smartfan settings, but in the BIOS disable the fan alarm. Just keep an eye on your temps.

 

[Ryland]

Yeah. It was set to AUTO which may have been causing issues since it probably should have been on PWM. I will play with it some more in a day or so once Im 100% sure that fixed it.

thanks.

 

[Ryland]

I reactivated the smartfan set to auto and the motherboard started whining about the fan not starting so I turned it back off. I will need to play with it some more I think.

 

[zagood]

All you have to do is go to PC Health Status in the BIOS and disable CPU FAN FAIL WARNING.

 

[Ryland]

Yeah I know. Im still curious as to why it started whining only after I installed the PCPC PSU. It never used to do that.