Odd clicking sound when SP3 is sleeping

[wynand32]

Okay, this is a weird one, which I've noticed only because the fan on an SP3 that I bought and returned failed and so I check my current unit every now and then for the same issue. Here's what it is: a clicking sound that I can hear where the fan exhausts on the upper-right hand quarter of the machine, but only when the SP3 is sleeping.

I'm not terribly concerned about it, except it seems to imply that there's some sort of electrical activity going on when you'd think there wouldn't be. I have no idea what might cause it, and I even have a hard time describing it--although, it ALMOST sounds like the fan is running at a very slow clip, because when you turn the machine back off you can hear the clicking sound seem to ramp up. Except not, because maybe the sounds are just melding together.

Crazy, I know, and mostly of passing interest. Anybody else have it?

 

[ipaq_101]

Maybe the fan is loose and hitting something inside?

 

[wynand32]

Well, the thing is it only makes that sound when the machine is sleeping. So, theoretically, the fan shouldn't be running at all. And I'm not sure at all that it's a mechanical sound; really, it seems like it's electrical, only it gets mixed up with the fan noise when the machine wakes up.

Note that I can only hear it when I put the vent up to my ear. So, it's not intrusive. I'm just wondering what could be causing it.