Something freaky happened to my iMac today

[suben]

Hi, I want to share this story with you.

I was updating my OS X to the new Yosemite and this is what happened.

While it was updating, something that looked like smoke, puffed from both sides of the iMac.

It kind of scared me, but the iMac didn't burn down and the updating kept going. I realized that it was just dust that the fan blew.

Now my iMac has the new OSX and is running just fine.

Anything like this happened to you?

 

[nufanec]

I have seen it happen before, sometimes during firmware updates the fans will run full but usually not during just software updates unless you have an older machine and it is having to do a lot of work.

Most likely to happen if your iMac isn't one that is driven too hard and the fans never really ramp up. Dust can accumulate on the fans and if they are only every idling then they won't spin it off - then when the fans are run full you can get a puff of dust released.

 

[fathergll]

While it was updating, something that looked like smoke, puffed from both sides of the iMac.

Puff of smoke? Did this happen in California or Colorado by chance?