Need help with a fan and a fan controller.

[Tim]

Hello,

I've got a fan controller (6-fan), and there is one particular fan that won't light up the LED on the fan controller no matter which position 1-6 that I plug it into, so I'd say it's obvious that the fan itself is what keeps the LED from lighting up.

The fan is a 250mm fan that has a black and red wire that was originally attached to a molex connexter. I cut off the molex connecter and attached the wires to a 3 pin female connecter that had 3 wires, black, red, yellow. I connected red to red, black to black, and I got rid of the yellow all together since there was nothing to connect it to. The fan works, the fan speed controller actually works slowing and speeding the fan up, but the LED doesn't.

On the fans PCB itself, I can see that where the black and red wires are soldered, there is a third spot that looks like it was meant to have another wire soldered. I tried making the LED on the fan controller come on by re-using the yellow wire and just touching it to that spot on the fans pcb, but nothing.

It's just an aesthetics thing I suppose, but is there any way to get this LED working, or am I just out of luck?

 

[mfenn]

The yellow wire on a 3-pin fan header is for RPM sensing, so that won't help you.

I'm assuming that the original Molex only had 2 wires. The red one should be +12V and the black one should be ground. Have you tried turning the fan controller to max? There may not be enough voltage otherwise to drive the LEDs. Have your tried plugging the fan directly into the motherboard? Have you tried a 3-pin to Molex adapter?

 

[Tim]

You've misunderstood, it's the LED on the fan controller that's not powering on, and this is no matter which 1-6 slot the particular fan we're talking about is plugged into. The fan itself has no LED's. Any other 3 pin fan I have, when plugged in 1-6 on the fan controller, the corresponding LED on the fan controller turns on.

Example: 250mm problem fan plugged into spot 2 on fan controller, everything works but the LED on the fan controller. Remove 250mm fan, put in spot 3, plug 120mm fan into spot 2. Spot 2 LED lights up, spot 3 doesn't.

 

[mfenn]

You've misunderstood, it's the LED on the fan controller that's not powering on, and this is no matter which 1-6 slot the particular fan we're talking about is plugged into. The fan itself has no LED's. Any other 3 pin fan I have, when plugged in 1-6 on the fan controller, the corresponding LED on the fan controller turns on.

Example: 250mm problem fan plugged into spot 2 on fan controller, everything works but the LED on the fan controller. Remove 250mm fan, put in spot 3, plug 120mm fan into spot 2. Spot 2 LED lights up, spot 3 doesn't.

Oh, my bad. I indeed thought you were talking about LEDs on the fan.

I'm thinking that the fan controller might use the RPM sensing wire (the yellow one) to determine whether or not to light up the LED. That makes some sense to me from a design point of view because the LED would go out if the fan wasn't spinning for whatever reason.

If that's the case, then you'll have to either figure a way to trick the controller or just not worry about it because there is likely no RPM sensing hardware on your fan.

 

[Tim]

Now that you mention it, it's GOT to be because of the sensing wire, because when you turn the knob from low to higher, the LED changes colors... how else could it do that without sensing the RPM (Duh moment)

I really would love to figure out a way to get this working... 1 light not lit up out of 6 just really bothers me and looks weird.

 

[Paperdoc]

Check this forum thread on Antec TriCool fans. (I don't know which fan you have.) One poster claims (and shows pictures) he found the correct signal point in the fan to connect to and get the speed signal pulse output that is normally on the yellow wire.

http://www.tomshardware.com/forum/287240-28-antec-tricool-case-fans