[SOLVED] my friends fan has been stuttering, he needs it for college, help would be appreciated.

[LoLgrunt]

the fan on his computer will run at high speed (loud noise) for about 3 seconds before descending into 1 second intrevals where it will sputter twice, be quiet for a second then stutter again, this happens 6 times so about 12 seconds total before the 3 second burst. i suggested maybe getting a new fan. any suggestions or ideas? much appreciated, thank you.

 

[drivinfast247]

What fan? What computer? Need more info!

 

[Owterspace]

Sounds like it’s out of lube. Find a way to lube it or replace it.

 

[Paperdoc]

This is what a normal fan control system will do in certain circumstances. This generally applies to all fan headers.

At START-UP, the fan should start at full speed and stay that way for a few seconds as the POST process completes. Then, as a temperature reading becomes available the automatic fan speed system slows the fan to whatever is needed to keep the system cool. That often is quite slow because the system already is cold from being shut down.

Once everything is running, the fan header monitors the speed signal coming back from the fan for FAILURE. On some mobos that means no speed signal because the fan really did stall; on others it means the fan speed fell lower that a limit you can configure in the header's settings. If that happens, the mobo will intervene and force the fan to speed up a lot to ensure it gets going again, then revert to the normal temperature control strategy which will slow the fan down.

Your description sounds like, after the fan is running, it goes so slow that "failure" is detected repeatedly and the mobo is trying to get it to re-start each time. That may be because the fan really is stalling. Or it may be because the fan's control signals are setting it to run slower than the low-speed limit set for its header. I suggest two possible paths, depending on what really it happening.

1. Open the case and observe the fan that is causing you concern as you start up. Once it starts doing its repeated "stuttering" and speeding up, does it actually stall, or nearly do that? This would indicate that it is being told to run too slow, slower than its rated minimum speed. First, look up the specs for that fan on the maker's web pages. Then go into BIOS Setup for that fan's header and look for a place to set the minimum speed it will tell the fan to do. IF you have already created a custom "fan curve" you are using, change that to raise the lowest speed setting at low temperatures. On the other hand, IF you have not done that and this is happening becasue you already are using the pre-programmed default settings, then you probably should create a custom "fan curve" and use it, and include in that a higher minimum speed than the default settings were using. In either event, that should prevent the fan from being told to run too slowly.

2. IF, on the other hand, you find that the fan never stalls and appears to be running smoothly until something forces it to speed up and then slow down again, MAYBE the mobo has the wrong setting for a minimum speed that is causing it to call "failure" when the fan is NOT in danger of stalling. Again, check carefully what the fan specs say is the real rated minimum speed for this fan and compare that to what the BIOS screens say the speed is. If the fan is running smoothly at a speed higher than its spec'd minimum and still is doing this odd behaviour, the header's "failure" detection limit may need to be changed. Some mobos do not let you do that - they simply have no such option. But if there is an option to set the fan's low-speed alarm limit, adjust that to what the fan's specs say it should be. That MAY solve the problem if the automatic control system is already set never to go below that new limit anyway.