CPU Fan Speed Just Went Through the Roof - Not Overheating...

[croSSeduP]

For some unknown reason, my CPU fan started running at about twice the speed that it used to. It is running at like 6200 rpm! It is making a ton of noise, and is even vibrating the table the machine sits on. The only thing that I changed was that I unplugged the NB fan to reposition it, and plugged it back in. Then the CPU fan started going crazy. Even at "idle" it is running over 4000 rpm w/ SMART fan control on. Any ideas?

 

[MindoverMaster]

Think your fan's balance is off. You try controlling it in BIOS?

 

[Slaymate]

How did you reposition the NB fan? Have you tried putting it back as it was originally?

Double check the cpu heatsink/fan assembly. You may have accidentally dislodged it without realizing it.

 

[croSSeduP]

Cannot control the fan speed in BIOS; tried that.
All I did w/ the NB fan was turn it around so that it was blowing the other way. That The CPU fan started going off after I had re-mounted the NB fan and then plugged it into the NB header.
I did not know the heat sink/fan off it's seat.
What about just clearing the CMOS?

 

[MindoverMaster]

Could try resetting BIOS. the NB HSF should be blowing on the heatsink.

 

[Slaymate]

Turn the fan back around, that could very well be the problem. Heatsinks are designed to be cooled with the air blowing in a particular direction. By switching it, that part of the system is probably running hotter and it's causing the rest of the system to run hotter. The hotter it gets the faster the fans will try to spin.

 

[croSSeduP]

No. That is not the issue. The fan connected to the NB fan post is just a case fan. It was blowing out, and it really should have been blowing in. There is not, nor has there ever been, a fan on the north bridge.

 

[MindoverMaster]

does it do the same when not fastened down on it, but plugged in? Like hold the outer edges with your hand.