Question Fans connected directly to the PSU are not running ?

[blackkeys1098]

I just reconfigured my fan setup in my micro atx case, replacing one fan and installing 4 all new ones in a way I've never done it before. Unsurprisingly, the 4 new ones aren't spinning.

I have 3 total PWM fan slots on my motherboard; 1 for the cpu fan, 1 for the built in intake fan and 1 for the 140mm rear exhaust fan.

The case needed additional air flow so I installed 4 more 140mm fans identical to the exhaust fan on both sides of the case. I originally used PWM splitters to connect the fans to the motherboard and, while they ran, it seems like too much to run off the motherboard.

The fans came with PWM to 4 pin molex adapters so I reconfigured it; running a 6 pin cable directly out of the PSU with 4 daisy chained 4 pin molex hookups and (using the adapters) connected all four fans to the same cable coming directly out of the PSU.

While they aren't tapped into the mobo, they have direct access to power and I figured they'd just run at full speed at all times. Instead, they're not running at all.

I've never used molex to run fans before, is there a step I'm missing?

 

[stonecarver]

so I reconfigured it; running a 6 pin cable directly out of the PSU

Can you show a picture.

 

[blackkeys1098]

Can you show a picture.

I can later. But is there anything to do here other than daisy chain the fans via molex and connect straight to the psu?

 

[beyondlogic]

I can later. But is there anything to do here other than daisy chain the fans via molex and connect straight to the psu?

check molex connectors are correctly seated the pins in the fan connector are very fiddly

 

[Paperdoc]

In almost all cases the rule is that one mobo fan header can supply power to several fans connected to it by a Splitter as long as the total max load of all the fans on that ope header does not exceed 1.0 A. So you need to know for each of your fans its max current rating in Amps. Then you just add up all the one on ONE header.

So we can help with that, post back here with:
(a) the maker and exact model of your mobo (so we can check it limit to be sure); and, (b) the maker and model of each case fan you are using, so we can look up its max current spec.

My guess is that there is NO problem with three fans each on your two mobo fan headers via Splitters, but that info would allow us to verify exactly.

By the way, there is another option called a HUB which works differently from a Splitter and avoids the current limit. But you may not need that, and it sounds like you already have some Splitters you were using.

 

[CountMike]

I can later. But is there anything to do here other than daisy chain the fans via molex and connect straight to the psu?

Yes you can use fan splitter cables.
Tjdr. Some PVM (4pin) fans can't work with just 12v power from PSU.