Case fan randomly goes to 100%

[dannolt]

So I been having this problem for a long time now pretty much since I built my pc, which was back in january of this year. The fan goes to 100% and stays there I can't do anything with AI suite 3 to lower the RPM, haven't tried any other software tho, the only fix I know is to restart my pc then it goes back to normal and I can control the RPM. My case is Corsair Spec-03 with 3 fans 2 in front and 1 in the back which has this behavior, all of them are connected to the fan headers on the motherboard(ASUS ROG STRIX Z370-F GAMING) the back fan is connected to the chassis fan 2 header on the motherboard and it's and the fans are set to "Standart" in fan expert. So what could be the issue, could it be the fan or something else like a sensor and how should I go about to troubleshoot it ?

The PC specs:

OS: Windows 10 Pro

CPU: i5-8600k

RAM: 1x8GB 3000mhz DDR4

GPU: Aorus GTX 1060 Xtreme Edition 6G

MOBO: ASUS ROG STRIX Z370-F GAMING

PSU: Corsair RM650X

CASE: Corsair Spec-03

SSD/HDD: Barracuda 1TB, Samsung 850evo 250GB

 

[EsaT]

Sensor would likely work either normally or not at all instead of such intermittent problem.

So likely reason is simply bugged fan control.

Guess you could try if some SpeedFan would work with motherboard.

[LogicalDrm]

When you say you can't do anything with Fan Xpert, what do you mean? There's no curve? Everything is greyed?

 

Have you set fan header to DC/PWM according to which fan it is? Is BIOS and software both updated to latest versions?

 

This sounds like you are using aggressive fan curve where some software uses CPU for few secs and raises temps over threshold to bump rpms.

[dannolt]

3 hours ago, LoGiCalDrm said:

When you say you can't do anything with Fan Xpert, what do you mean? There's no curve? Everything is greyed?

 

Have you set fan header to DC/PWM according to which fan it is? Is BIOS and software both updated to latest versions?

 

This sounds like you are using aggressive fan curve where some software uses CPU for few secs and raises temps over threshold to bump rpms.

Here is the the fan profile for that fan, I have the software updated to the newest version but the BIOS has a never version so I'll try updating and see if it happens again because it doesn't happen that often but I would like to know why it happens and fix it. Ohh yeah and I'll check if it's set to DC or PWM too.

[dannolt]

+ Even if my CPU went over 75C in which case all of the fans should go to 100% and then they should go down with the temperature, right ? And about the curve when the fan goes to 100%, it shows the rpm of the fan but I can't lower it by changing the curve.

[LogicalDrm]

2 hours ago, dannolt said:

+ Even if my CPU went over 75C in which case all of the fans should go to 100% and then they should go down with the temperature, right ? And about the curve when the fan goes to 100%, it shows the rpm of the fan but I can't lower it by changing the curve.

That sounds like its bug in software. Does this still happen if you set max rpm to 80% or lower?