Working on my sister's 2005 Ibook.
Anyone know if the fan should be running all the time or just at a certain temperature?
I installed IStat and it shows the temp reaching 47 degrees but the fan hasn't come on yet.
I actually have the bottom off the Ibook and can see the fan. Initial problem was that the IBook would not come on. With the cover off, it boots up, which obviously points to another issue...

Still using a G3 Powerbook to play iTunes through the stereo. Did not even know it had a fan until this summer, when the room temp soared to the mid 80s (F) at which point fan kicked in and ran nearly continuously.

Handled lots of G4 iBooks when working for the school board. Cannot ever remember hearing a fan kick in at normal room temps.

Fans should only come on when needed, so it should not be running all the time.

Fans should only come on when needed, so it should not be running all the time.

Fans in all Macs run all the time except when in sleep mode. If you can't hear them, it does not mean they're not running, but rather, they're running at a fairly low RPM.

The ibook fan should come on only when needed. I will note that on the iBook that is still used sometimes here, it is needed more and more often. Just surfing the Internet and encountering a gazillion plug-ins and video content significantly taxes the processor.