Question Chassis Fan Spiking to 15,000 RPM out of random?


Jul 12, 2016
So yesterday, my computer's fans sounded really quiet and good. I shut it off to go to bed.

As i shut down my computer, it said 'configuring windows update'. So i thought i'd just let my computer do its thing -- and turned off my monitor.

This morning, i woke up and my computer's fans started up pretty loud. Temps on everything were good (looking and HWMonitor). It was staying the same, cool tempatures... but for the life of me couldn't understand why everything sounded just a bit louder. Usually, i can barely hear them. I started monitoring my HWMonitor on the fan's RPMs, and everything seems to be running at around 300-1,000 RPM. However, one of my chassis fans would randomly spike to 15,697 RPM then go back down to 400. I suspect this maybe one part of the issue? So i have a couple questions:

Is this a case of a dying fan or failing sensor?

Would a windows update (though, i did check to see the latest updates but it seemed to say it was a month ago) change the fan BIOS settings?

What are your fan curves set at?

I need help with this issue. Its driving me nuts, and for the life of me -- cannot remember if my fan curves are the same as before or they were changed (even looking in the BIOS). Thanks ahead of time!