DSM-G600, DNS-3xx and NSA-220 Hack Forum

I've had my 323 for about 5 months, and recently I've noticed the fan speed oscillating a lot, even under minimal load.  It's like the fan controller hardware is busted; I'd try and set a speed but the fan can't maintain that speed and kind of oscillates around the desired RPM.

Everything seems to work, but the box is located right on my desk and the fan gets loud and quiet again about every 20 seconds, so it's quite annoying.

Yesterday I installed the fanctl-1.tar.gz package (I'm using ffp), and logged the output from it for about a day.  I've included the graph of the fanspeed.  (The x axis is the number of 30 second time periods).

The weird features are the peaks above 4000 RPM and of course the 0 readings.  I don't know if that kind of noise is common or not. You can see how the fan set point changes in the piece wise linear fashion, and there is small magnitude noise around these setpoints (in the 3K RPM range).  Since the oscillating behavior I'm experiencing is happening faster than every 30 seconds, I am only graphing parts of this.

As I said, my hypothesis is that the fan controller is busted, and that's why this is so noisy.  Does anyone else have any insight here?

Thanks!

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