Fans not working on low setting

D1craig · 27 Oct 2021 at 02:34

So I've had my rads setup up for a few months now externally with 6 fans on them connected to a fan hub that has a switch with low, off or high settings. It has worked flawlessly since I got it. The hub is connected to my psu by molex connector. Today I noticed my water temp a fair bit higher than I've noticed it before - 40C, I know this isnt too high but it prompted me to check the fans and a good job because on the low setting my fans don't work, they just gradually come to a stop.

What could cause this to have happened? I do have some replacement hub and cables etc etc in my basket but I would like to know what caused it first.

Five.Stars · 27 Oct 2021 at 16:24

Fans usually have a minimum speed that they will spin at, especially voltage controlled fans. It could be that the low setting is not providing enough voltage to the fans.

Five.Stars · 27 Oct 2021 at 16:25

Although it is strange that it worked previously on the low setting, so that would seem to rule out my theory.

D1craig · 27 Oct 2021 at 22:12

im guna buy some of them noctua LNAs and see how that works out. im am going to be moving rooms with my pc sometime so not going to go to deep into it lol

Drumroll · 6 Nov 2021 at 21:23

May be some issue with the hub.
Most of the PWM fans I've used are fine at 25% plus.
What RPM the fans are supposed to be at low speed when connected to the hub?
I would try to set the same speed and connect them to the motherboard, just to confirm the issue is with the hub, before start ordering parts.