Weird chassis-fan problem...

[Yoshi64]

I have a Enermax 80mm chassis-fan, where you can control the fan-rpm with a little nob that you turn.

When I connected this fan to my new mainboard, an ASUS A8N-E, it didn't start. I connected it to the CHA1_FAN-header, which is the one closes to the intake fans in the front.

The weird thing is that the fan starts and works fine if I just turn the rpm-nob a bit. I just increase the rpm a bit, and the fan starts. Then, when it has started, I can decrease the rpm again and it keeps going. This is a bit annyoing, anyone have any tips?

 

[pcman83]

The fan doesnt have enough power to spin in the beginning. You are jump starting it. Then it has a enough momentum to run at a lower rpm. Then when it starts again it doesnt have enough power and the same cycle starts. You should get an rpm where it will start by itself and leave it there.

 

[Luckyboy1]

What he said!...

If you are like, obsessive about it, you can make a startup capacitor circuit to solve the problem, but who needs that mess to solve what can be so easily managed the way you do it now?

 

[Zepper]

You have to turn off the mobo's built-in fan control (for that fan connector only if possible) either in the BIOS or your mobo's health monitor program (usually called Probe) or remove (or bypass) the fan control that came with the fan (or just turn it up full and leave it), or connect that fan directly to a drive power connector from the PSU. The concept is that you want only one speed control mechanism on any given fan (assuming the mobo connector can supply adequate power for your fan - most are limited to 0.5 Amp or less).

.bh.

 

[Yoshi64]

The weird thing was that I never had this problem on my old Abit AN7 (Nforce 2 Ultra 400).

I tried increasing the rpm to the limit I accept (~2000 rpm) noise wise, but that wasn't enough to get it started.

Zepper: I have the ASUS Q-Fan disabled, so it shouldn't be interfering (sp?)

 

[Zepper]

Fans have a starting voltage spec that is often higher than the minimum possible running voltage as inertia and perhaps more friction have to be overcome to start the fan. Once started, then the fan can be cranked back to the run level you want. As mentioned above, a capacitor circuit could be rigged to give the fan a starting bump and you could then leave your fan control set at the fan speed you want. But I'd still measure the voltage you're getting at the mobo connector just to be sure.

I don't think the Abit nForce2 mobos had built in fan speed control, but I could be wrong.

.bh.