Fan turning on and off

[Cave Man]

I have an i7 MBP and this morning I discovered that its fan is turning on and off at about 2 second intervals. It only occurs when the lid is closed and (seemingly) when the battery is at full charge (i.e., the mag safe is green). As soon as I open the lid the fan comes on and stays on for 30 seconds or so then shuts off as if the system has cooled. Any ideas what this is about?

 

[mrsir2009]

So your saying when the battery is at full charge and the laptop is asleep the fan revs ? Like VVRRROM..... VVROOOOM!....?

 

[Cave Man]

Yes, comes on, then off. It's weird.

 

[AlphaDogg]

Would you mind taking a video? It would further assist us, in trying to help you.

 

[mulo]

they shouldn't turn off, you sure their not just running so quiet you can't hear them? ie the usual 2k rpm.

 

[greenchiliman]

What kind of surface do you have it on? Maybe the heat from the battery at full charge and plugged is pushing your temp over the limit to where it triggers the fans. Seems like a weird scenario for a new MPB.

 

[Giuly]

Try resetting the SMC.

 

[Cave Man]

Would you mind taking a video? It would further assist us, in trying to help you.

There's not much to put on video. The fans spin up for a couple of seconds, then go quiet for a couple of seconds. This repeats continuously, but only with the MBP closed and when the battery is fully charged.

they shouldn't turn off, you sure their not just running so quiet you can't hear them? ie the usual 2k rpm.

That may be; if they're not turning off they're so quiet that I can't hear them.

What kind of surface do you have it on? Maybe the heat from the battery at full charge and plugged is pushing your temp over the limit to where it triggers the fans. Seems like a weird scenario for a new MPB.

Upright in my bag or sitting on top of a chair. In each case the vents are not obstructed. But the batteries sure are hot.

Try resetting the SMC.

That didn't work, unfortunately.

Thanks for the suggestions - keep them coming!

 

[Cave Man]

I ran the battery completely down, then recharged and the problem seems to have gone away. Weird.