# Fans displaying unusual behavior



## Neutral12 (Jun 27, 2013)

Information:

This build is the recommended techsupportforum build from 2013, and I'm using the fans that came with my case. I included information I thought would be relevant to this thread:

*Case/Cooling:* Cooler Master HAF 922 - High Air Flow Mid Tower Computer Case with USB 3.0 and All-Black Interior

*Power Supply:* Seasonic SS-760XP2 ATX 12V/EPS 12V, 760W, 80 PLUS PLATINUM Full Modular certified Active PFC Power Supply New 4th Gen CPU Certified Haswell Ready

*Motherboard:* GIGABYTE GA-Z87X-UD5H LGA 1150 Intel Z87 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard with UEFI BIOS

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Situation:

So lately I've been noticing with my custom build computer that the fan(s) are behaving very unusually. This is primarily noticeable on the fan that's at the top of the computer case. 

Upon starting the system, I noticed that the fan is starting to make a moderately loud noise, and that when the computer is shut down, instead of the fan gradually slowing down as it turns off, the fan instead stops right in its tracks after the first second or so of the computer turning off.

My immediate course of action was to open up the case and inspect the connections, all of which seemed to be perfectly snug. Despite this I reconnected them anyways just to see if it was a lose connection, but despite that, the fan was still behaving weirdly.

I then decided maybe it's some lose screws. I made sure the screws that held the fan onto the case were securely snug, but still, the fan was behaving weirdly.


So in conclusion I have absolutely no idea why my fan(s) started doing this. Previously they were very quiet and would naturally and gradually slow down upon shutting down. Now what happens, for an unknown reason, is upon starting up the computer, the fans appear to be making a louder noise than usual, I believe they may be performing less than usual as well. Then when I turn the computer off, it stops spinning almost immediately which isn't usually what happens.

While it does appear to fix itself after its been on for roughly 5 minutes, I still believe this can be a potential issue and I would like to possibly troubleshoot it.



Thanks for the support.


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## Bill_Bright (Dec 17, 2004)

> instead of the fan gradually slowing down as it turns off, the fan instead stops right in its tracks after the first second or so of the computer turning off.


That is normal for many DC fans. If you carefully, and slowly turn the fan blades with your finger, if you can feel and see where the fan has "steps" the blade wants to stop in. This is where the internal magnets are centering. When you shut down the computer and remove the voltage from the fan, the magnets quickly bring the fan to a full stop. 

So unless the fan is making grinding noises or creating excessive vibrations indicating the bearings are failing, I would not worry about it. Just keep the fan and vent (and the case interior) clean of heat trapping dust. 

I note at times you say fan and at other times you say fans. Where do these fans get power - directly from the PSU or are they connected to motherboard fan headers. If the PSU, then there's nothing you can do. If connected to motherboard fan connections, you might look in the BIOS Setup Menu to see how (if) they are being speed controlled from there. A recent BIOS update may have changed a fan control setting.

If the fans are making grinding noises or creating excessive vibrations, the bearings will likely soon seize and the fans will need to be replaced.


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## Neutral12 (Jun 27, 2013)

Yea sorry, I kinda switched between fan and fans because I wasn't 100% sure if it was all of them or if it was simply the one on the top of the case. To answer your question though, these fans get their power from the motherboard. I took a look at the BIOS as you recommended and I noticed there were fan settings. Next thing you know, I played around with that, and things appear to be operational again like it once was.

Thank you so much for your support.


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## Bill_Bright (Dec 17, 2004)

Great! Glad you got it sorted out and thanks for the followup!


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