[alltoasters]

I've got a couple of noisy fans i wanted to quieten down, so thought i would try undervolting them. However the guide I used wasn't perfect, so I thought I should just ask for a second opinion to see if what ive done is right.

I took the black fan cable out of the pin with the black molex lead, and soldered it onto the lead with the red molex lead (but not the red fan lead obviously) Blurry Pics included

Also, I don't get the thing about power. Am I supposed to plug the fans molex in to the psu, then put something on the fans other connector? or am I supposed to take one of the wires with molex connectors off the psu, and have nothing else on it?

 

[dragosmp]

Hey mate, can't understand much of those pics. Actually it's as simple as that to put a fan on 7V in stead of 12V:
1. Start by identifying the GND, +12V and tachowire in the fan connector
http://www.allpinouts.org/index.php/..._Fan_Connector

1 GND black 2 +12VDC or +5VDC red 3 Tachometric Signal yellow
2. To power the fan on:
*12V - put fan's red wire @12V (yellow on the molex), GND to black molex GND
*5V - fan's red wire @5V(redon the molex), GND to black molex GND
*7V - fan's red wire @12V and fan's GND @ +5V (so that 12-5=7)

3. Word of caution, not all fans have these three wires color coded this way. However GND is always on position 1, power on position 3 and tacho on position 2.

Hope this helps

 

[alltoasters]

Thats how its wired up, but its a molex fan without a tacho.

How am I supposed to plug it in though, I've read something about sticking too much backwards on the 5v rail. I've drawn a diagram to show how my stuff is wired up. Is it safe to just stick it on one of the unused molex connectors, I don't want a blown up psu.

 

[mr soft]

Yes it´s wired right for 7v . Just make sure the molex pins are not loose , a good idea is to cover that other end on the molex with electrical tape so you don´t accidentally plug something in .