Fan or Hard Drive Failure

Thanks a lot Dan !

Do you suggest to replace the sensor ? the fan ? both ?

@Dom - the fan needs to be replaced and if the drive is not the original one or was removed only to have the SSD mounted under the optical drive, you'll need to add in the sensor.

@danj I assume that if the iMac ran for years with only the SSD installed, that sensor has already been added am I right ? So a fan replacement would be enough ?

(Might a dust cleaning be enough ?? )

@Dom - I hate to assume as it really means Axx out of You & Me! ;-}

The fan error is a hardware failure not dust buildup alone. As far as the sensor, as you need to get to the fan you'll have a chance to see if it's present or not.

So let's say someone just used some fan controlling software to override the SMC logic. So it may appear all is well and good, but in truth its not!

First SMC will slow down the CPU's clocking so you aren't able to get the full systems performance! And as the software is limiting the fan's speed your system could still cook!