Where to plug in case fan or PS lead??

[BoboKatt]

Hi all,

I've built now a few systems and this is driving me nuts. On my boards I only have two of the 3 pin connectors that you can plug in fans. One is for the CPU fan. which I connect of course.

Then in the manual it states the other is for the case fan. However the case fans I have in all these systems are all 120mm ones and have a regular Molex connection that I connect to the ones that from the PS that say FAN ONLY or if I want them to spin at full speed I connect them to a regular one. The Power Supply also has a lead that happens to be a 3pin one? THUS where does the lead from the PS connect to and what is that for? Will it slow the fan down from the PS? Bahhh. I wish boards would have 3 or 4 of these connectors. Are fans connected to these onboard connectors the only ones that are controlled speed wise for temperature or also the molex ones?

Thanks

 

[peleejosh]

THe fan lead from your psu is for monitoring your psu fan, connect it to your mobo. The fans that are connected to molex conntectors runat full speed and are not temp controlled. Generally it is not a good idea to connect fans, especially big ones that pull alot of juice, to your motherboard. Ideally all fans should be connected to a fan controller. Also you can mod the molex connectors on the fans to 7 or 5 volts to get them to run slower.

 

[Zepper]

Yes, the three wire lead from the PSU is just the fan sensor - the power is supplied inside the PSU itself. Connect it to a mobo header so that you can monitor the 2nd most important fan in your system after the CPU - and set an alarm for it in your hardware monitor software. If a PSU I get doesn't have the sensor wire, I immediately replace the PSU fan with a 3-wire fan just for that purpose. One of my PSUs almost lost its 'magic smoke' when the fan went out (and all I had was my nose for an alarm ) - no more!

.bh.