CPU Fan not running

[minY]

So recently I started building a 2nd computer for just work stuff and after I put everything together, the CPU fan doesn't spin at all! The computer is booting up perfectly fine and everything else is working like its supposed to, except for the fan. I opened up the computer again and replugged the fan into the CPU_Fan header. I am unsure if it is fine to plug it into the SYS_Fan header so asking for tips before I do anything!

Motherboard: Gigabyte AX370 Gaming Motherboard (America)
Processor: AMD Ryzen 5 2600
CPU Fan: AMD Wraith Stealth (4 Pin)

Link to motherboard manual: https://www.gigabyte.com/us/Motherboard/GA-AX370-Gaming-rev-1x/support#support-manual

[r.linder]

Are you sure the fan isn't just idle and only ramps up when necessary?

Did you check BIOS?

BIOS might dislike if the CPU_Fan header isn't populated

[Magma Dragoon]

Most motherboards by default have fans at 100% during post.

CPU fan goes in the CPU fan header, case fans go in sys fan headers, you're doing it right. Try plugging a case fan into the cpu fan header and the cpu fan into a sys fan header, that way you can see if the fan or the header is the problem.

[Jaunitta 🌸]

Is it connected to the right fan pins on the motherboard.
As your motherboard doesn't provide those details for me in my country I will have to use one I sourced
Connect the CPU fan cable to the connector on the motherboard labeled CPU_FAN.
https://event.asus.com/2013/mb/pc_diy_guide/images/03_c05.jpg
Page 4
http://download.gigabyte.us/FileList/Manual/mb_manual_ga-ax370-gaming-k7_e.pdf

[minY]

Originally posted by Escorve:

Are you sure the fan isn't just idle and only ramps up when necessary?

Did you check BIOS?

BIOS might dislike if the CPU_Fan header isn't populated

I went into Gigabyte Smart Fan and the fan is "on".

[minY]

Originally posted by Magma Dragoon:

Most motherboards by default have fans at 100% during post.

CPU fan goes in the CPU fan header, case fans go in sys fan headers, you're doing it right. Try plugging a case fan into the cpu fan header and the cpu fan into a sys fan header, that way you can see if the fan or the header is the problem.

I switched the cpu fan and the case fan and the cpu fan ran perfectly fine and the case fan didn't... So the issue appears to be the CPU_Fan header or something in BIOS and I am too stupid to notice...

[minY]

Originally posted by Jaunitta 🌸:

Is it connected to the right fan pins on the motherboard.
As your motherboard doesn't provide those details for me in my country I will have to use one I sourced
Connect the CPU fan cable to the connector on the motherboard labeled CPU_FAN.
https://event.asus.com/2013/mb/pc_diy_guide/images/03_c05.jpg
please scroll down to IMAGE 9
https://event.asus.com/2013/mb/pc_diy_guide/step.htm

This video may be of help not sure so hopefully provides you some keys. Yeah youtube has guides for everything
https://www.youtube.com/watch?v=NMn-9V3WbCw

That video pretty much did everything I did... except that motherboard's cpu fan header is the same as the cpu opt header... For me they are 2 separate headers... I will attempt to plug into the CPU_OPT header and update you!

Update: CPU_OPT doesnt work either... Thinking of just plugging in the fan into the SYS_Fan 2 header...

[UTFapolloMarine]

i say get a better cooler like above said, or try updating the mobo to be sure its all properly compatible and not overheating

[minY]

Originally posted by POUusnavy:

i say get a better cooler like above said, or try updating the mobo to be sure its all properly compatible and not overheating

The cooler isnt the issue. I plugged in the case fan into the cpu fan header and it didn't spin, but when I plugged in the cooler into the sys fan header it worked perfectly fine... Either something is broken or Smart fan settings is messed up

[UTFapolloMarine]

Originally posted by Irene ♥:

Originally posted by POUusnavy:

i say get a better cooler like above said, or try updating the mobo to be sure its all properly compatible and not overheating

The cooler isnt the issue. I plugged in the case fan into the cpu fan header and it didn't spin, but when I plugged in the cooler into the sys fan header it worked perfectly fine... Either something is broken or Smart fan settings is messed up

burned out your 3 pin update the mobo

[minY]

Originally posted by POUusnavy:

Originally posted by Irene ♥:

The cooler isnt the issue. I plugged in the case fan into the cpu fan header and it didn't spin, but when I plugged in the cooler into the sys fan header it worked perfectly fine... Either something is broken or Smart fan settings is messed up

burned out your 3 pin update the mobo

I am not overheating yet so... I will keep you updated lol

[minY]

Originally posted by POUusnavy:

Originally posted by Irene ♥:

The cooler isnt the issue. I plugged in the case fan into the cpu fan header and it didn't spin, but when I plugged in the cooler into the sys fan header it worked perfectly fine... Either something is broken or Smart fan settings is messed up

burned out your 3 pin update the mobo

Update: There are no BIOS updates... starting to think the cpu fan header is actually burnt out and just might use sys fan header...

[UTFapolloMarine]

Originally posted by Irene ♥:

Originally posted by POUusnavy:

burned out your 3 pin update the mobo

Update: There are no BIOS updates... starting to think the cpu fan header is actually burnt out and just might use sys fan header...

just go for a whole new board you risk destroying the whole system

[Spec_Ops_Ape]

Go into the BIOS and under smart fan 5 you can tune the sys fan header to respond to your CPU temps.
Edit: you can also install the Gigabyte App Center and then SIV and tune your fans in there.

[MrL0G1C]

Originally posted by Spec_Ops_Ape:

Go into the BIOS and under smart fan 5 you can tune the sys fan header to respond to your CPU temps.
Edit: you can also install the Gigabyte App Center and then SIV and tune your fans in there.

Agree, there is a chance it's just the fan curve although it's unlikely because fans will typically spin fast until the BIOS has worked out what it's doing after second or two.

I wouldn't worry about 1 fan header not working, I've been running a motherboard with a borked memory slot for many years, everything else has worked fine during that time. I sent back a motherboard with dead on-board audio, again everything else worked fine and likely would have for years. Lesson learned - test everything.

Still though if the motherboard is new then send it back because you might want to add fans in the future and no point taking any risk even if the risk is small. If it's old, personally I'd run with it.

[Magma Dragoon]

Originally posted by Irene ♥:

Originally posted by POUusnavy:

burned out your 3 pin update the mobo

Update: There are no BIOS updates... starting to think the cpu fan header is actually burnt out and just might use sys fan header...

It's defective, return it and get a new one