BleepingComputer.com: Q-fan Enabled; Cpu Hot?

OK!

This adaptor shouldn't be necessary if your motherboard already has a 3-pin fan header such as CHA_FAN, and connecting the fan to this one on the PSU lead (what I referred to as the PSU having a dedicated fan connector) will not allow the fan speed to be controlled. The single white wire is the tacho output to let the system report the fan speed.

If the fan is plugged into the one marked ??, and the white one plugged onto one of the motherboard fan headers, the fan should run constantly at full speed and the BIOS/SpeedFan should show the fan speed. But they will be unable to change the speed. That can only work if the fan is also powered from a PWM controlled motherboard fan header.

Also, be very careful with the exposed pins on the ?? lead. If they touch any other components or the chassis while the system is running, there could be a damaging splat, and things would stop working...

garmanma, on Sep 19 2008, 05:29 AM, said:

Nope, your eyes are as good as always It's a single wire leading from the small connector..


Sorry, Platypus. I sort of understand what you're saying, but I'm not sure what I should connect to where...?

(What I'm wanting to do is be able to control the fan speed).

And If I don't need to use the exposed "??" pin, can I wrap it up or something, so it won't touch anything?


Thanks!

Yep, Garmanma's eyes are sound...

I expect your fan has a 3-pin wire lead & connector like this:



The black and red wires are earth and +12V, the third (often white or yellow) is the tacho signal that tells how fast the fan is spinning. The motherboard controls the fan speed by varying the 12V supply. It has to be plugged onto the matching motherboard header pins for this to work:



To make the exposed pins on that adaptor safe, you could wrap them with electrical tape. But as the connection is no use to you, you could simply unplug the adaptor (the middle section that you've got the word Fan right beside) and remove it from the PSU cable. Plug the two white Molex connectors back into each other where the adaptor came out.

Yup, that's the connector (the one garmanma was asking about, only a white wire coming out of it?)

That's exactly what I'm doing, ie. plugging that 3-pin one into my motherboard. Problem is..it's not working :S

The 3-pin adapter is connected to the exposed one, so if i unplug the adapter then I can't use the 3-pin one to connect to my MB...

Sry this seems confusing

This post has been edited by funnytim: 20 September 2008 - 12:53 AM

No, the 3-wire lead connector of the fan itself has to be plugged onto the motherboard header. The single white wire lead garmanma referred to is no use to you.

But I can't find anything that's a 3-pin and 3-wire connector from the fan...

The only thing there is (other than those two ones I was talking about above) is the PSU connector, a 4-pin one.

Ah, I thought you meant the Fan connection was the one that had the word Fan right next to it - it's the one below that, so your fan is like this one:



If that's it, you can't control the speed of that fan. You need the type in my picture link above with the 3 wires to a 3-pin connector. It has to go straight to a fan header on the motherboard like the CPU fan does, as we said at the start.

O i see...

That sucks..

So that means I can only use it by connecting it to the PSU directly ?
Then what would the 3-pin connector (w/ the one white wire) be used for? (it fits into the MB sysfan connector)

Your CPU fan connector should be 3 or 4 wires, not 1.

It's best to connect case fans directly to the PS, using the 4-pin connector previously pictured.

Louis

funnytim, on Sep 21 2008, 08:23 AM, said:

Yes, a fan with only a PSU Molex connector is really intended to be a secondary PSU cooling fan rather than a case fan.

The connector with the single white wire carries the tacho signal if a 3-pin type fan is connected to the ?? connector. It would most likely be plugged into a front panel fan RPM readout in a drive bay, or onto the motherboard to let the BIOS monitor the speed of a large fan that's connected to the PSU because it draws too much current for the motherboard connection. Even though a fan on that connector runs full speed all the time, using the tacho output as well enables monitoring to ensure the fan doesn't stop for any reason, eg sieze up

O...so that single white wire can only be used if I've connected another fan to it?

Yes, it only does anything if a 3-wire fan is connected to the ?? connector, then the white wire to the motherboard. But then you may as well just connect the 3-wire fan to the motherboard.

, too bad I can't control the fan speed...at least the fan's relatively quiet.

So then I can take out the adapter that houses the 3-pin and the "??" exposed pin and just plug the PSU directly into the fan.


Thanks very very much for your help! (Sorry it went a bit off topic, still related to fans though! :D)

funnytim, on Sep 24 2008, 02:51 AM, said:

Yes, and that eliminates the danger of those bare pins shorting.

funnytim, on Sep 24 2008, 02:51 AM, said:

Glad to oblige.