Fan problems *after* SMC update?

[jpsecher]

My MacBook 15" Retina (Mid 2012) has never had any fan problems.

But on 2013-03-30 (I believe) the fans started to give an annoying noise, which only stops when powering down. It is a constant noise that is there regardless of what processes are running on the machine.

From SystemInformation/Software/Installations (date sorted), I can see that an SMC update has been installed on 2013-03-24.

Data points: I have now installed the app "System Monitor" which reports that both left and right fan run at approximately 2000 RPM (and CPU temperature is 36C). Is that normal?

My question is, can the SMC update have caused this problem?

 

[B...]

2000 RPM is the lowest they go and should not be audible. Try an SMC reset in case the sensors are wrong and they are spinning up for no reason.

If that does not help, there could be something that came loose inside the fan, causing a kind of grinding noise.

 

[jpsecher]

Restting the SMC does not change anything, allthough I am not sure that a reset was actually performed; there was no feedback after the left Ctrl/Shift/Option + Power combo was pressed and released simultaneously. How can I check that?

 

[Queen6]

Restting the SMC does not change anything, allthough I am not sure that a reset was actually performed; there was no feedback after the left Ctrl/Shift/Option + Power combo was pressed and released simultaneously. How can I check that?

Run you MBP on battery, let it run down to 90%, attach the charger, then perform the SMC reset. The LED charging indicator will flip from red - green - red, this confirms the SMC reset.

 

[swerve147]

Data points: I have now installed the app "System Monitor" which reports that both left and right fan run at approximately 2000 RPM (and CPU temperature is 36C). Is that normal?

My question is, can the SMC update have caused this problem?

It's completely normal. Your fans will never spin down below 2K RPM even at idle. But they should also be inaudible at 2K unless you literally press your ear up to the chassis.

CPU temp actually looks good, lower than most at default.

I would agree with B that it might be hardware related