Case fans are spinning but they are not showing up in bios

[deathhater9]

I finally built my first pc after months of planning, and everything works except my case fans. I have 4 of them, and they are connected to a fanhub which is connected to one of my system fan headers not the psu. 3 of the fans work, while one does not, I tried switching around the ports on my fan hub and it made no difference, so I'm assuming that one fan is dead. The other three fans are working, but they are not showing up in the bios, it just says system fan 1 and system fan 2 are disabled. Besides the one random fan that doesn't seem to work, the other three are actually working , so I don't really know why they are no showing up in the bios. On a somewhat related note, is there a way to change fan curves without the bios?

[Stellaros]

If you put three of your fans into a fan hub that connects into a single fan header on your mobo, it will still show up and read as 1 fan. Totally normal.

 

You are still able to control those 3 fans, its just that they will be at the same speed/RPM.

 

 

[deathhater9]

On 11/28/2020 at 10:25 AM, Stellaros said:

If you put three of your fans into a fan hub that connects into a single fan header on your mobo, it will still show up and read as 1 fan. Totally normal.

 

You are still able to control those 3 fans, its just that they will be at the same speed/RPM.

 

 

Sorry, maybe I wasn't very clear. They are spinning, but none are showing up in bios. The only thing I see is my cpu fan It says all the other fans are disabled. 2 of them are PWM fans while one of them is not so maybe that's the reason? idk. 

[magedogtag]

I have a three way splitter but only one of the split lines has the sensor wire while the other two don't.  Took me over a year of frustration to sort that out.  Turns out that if the mobo can't sense the system fans things will work, just not quite right.

[problemsolver]

On 12/1/2020 at 9:37 PM, deathhater9 said:

Sorry, maybe I wasn't very clear. They are spinning, but none are showing up in bios. The only thing I see is my cpu fan It says all the other fans are disabled. 2 of them are PWM fans while one of them is not so maybe that's the reason? idk. 

TL;DR, it all depends on the hub and how it's setup.

 

• Depends on the hub you connected it to and depends on if the hub has 3 wires running to the motherboard. Not a 3 pin connector, but 3 wires. One is the sensor wire as @magedogtag mentioned.
• Then, it would depend on how the hub handles fans connected to the hub. So, the hub can only tell the motherboard one RPM on the sensor wire... it can't tell it 3 fans are connected, it can only report RPMs
• So, how does the fan hub work? Does it send the RPM of the first fan connector on the hub? Does it send the average RPM of all 3? (well, we know one of your fans is a 2-wire fan, so it definitely doesn't know the speed of that one) Does it pass through the sensor wire from one of the fan connectors? Who knows. You didn't post your fan controller, so we definitely don't know.