[Leica] OT: IMac trouble - CPU fan speed = 0rpm - experts welcome

[philippe.amard at sfr.fr (philippe.amard)]

It's all in the heading I think.

My 2009 24" aluminium Imac DuoCore 3.06 Intel, 2x2GB SDRAM, running  
10.5.8  tends to heat a lot - the upper left corner gets real hot when  
I process large batches of photos.

I've downloaded smcFan Control and it tells me that the CPU fan  
doesn't spin - 000rpm.

(The other 2 fans (OD-HDD) can be adjusted alright and, more  
specifically heard; so far so good).

OTT : When younger the mac "sighed" heavily when I resumed operation  
after it went to economy mode. It no longer does.

I don't know how to open a Mac to check that CPU fan and before I take  
it to the repair shop I'd like to know


- what the "normal" temps for the CPU are

- which temp NOT to exceed

AND

if any of you has encountered this problem what the outcome was.


Thank you in anticipation for informed replies.

Bien cordialement de Metz
Philippe, who hopes this won't degenerate into a "my PC never  ..."  
hijacking ;-)