iMac i3 - fan runs wild after HD upgrade

lefse

macrumors member
Original poster
Jul 11, 2008
89
0
I bought a Seagate Barracuda XT 2TB (ST32000641AS) to replace a the 500GB Seagate hard drive that came with the machine (ST3500418AS).

Same brand, same connectors, though the hard drive fan now spins up to over 5000rpm after a few minutes. Tried SMC reset, but no change.
I am now using smcfancontrol.app (2.2.2) to get the hard drive down to a half way acceptable 2500rpm.

The temperature value of the new hard drive does show up in the istat pro widget (29c), however, in the slightly older smsfancontrol.app (2.2.2) it reports the temperature as zero.

Anyone who have had experience with this? Did some googling, and it seems to me that Apple adds special firmware to these drives.
 
Last edited:

lefse

macrumors member
Original poster
Jul 11, 2008
89
0
Have you contacted Apple?
No. I believe the hard drive in iMacs aren't seen as user replaceable.
Either way, there is no point in sending it back to Apple - the machine does work perfectly well with the original HD.
 

TMRaven

macrumors 68020
Nov 5, 2009
2,099
1
That temp sensor was only designed to work for the hdd that was already in the iMac. You'd have to go back in and short it out, or buy a new temp sensor.
 

lefse

macrumors member
Original poster
Jul 11, 2008
89
0
That temp sensor was only designed to work for the hdd that was already in the iMac. You'd have to go back in and short it out, or buy a new temp sensor.
Why would I buy a new temp-sensor? The sensor is _in_ the hdd.
And if i short it, what good would that do? I can still control the fan manually from smcfancontrol.app.
 

lefse

macrumors member
Original poster
Jul 11, 2008
89
0
https://forums.macrumors.com/threads/808178/


If you're fine with controlling the fan manually from the fan control app, I guess you've got no reason to ask for our help do you?
I am obviously not fine with controlling the fan manually - else I would not have asked if anyone had experience with swapping hdd's in an iMac i3 (or i5/i7).

The new iMacs reads the temperature from an internal sensor _inside_ the hdd.
Hence have I bought another hdd of the same brand with the same temperature sensor-connection next to the sata/power slot.

Shorting the sensor is for situations where there is nowhere to plug the sensor connector. Your SSD-upgrade links are therefor useless.

I wish people would care to read a bit more, before showing off their diehard ignorance
 
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John T

macrumors 68020
Mar 18, 2006
2,114
6
UK.
No. I believe the hard drive in iMacs aren't seen as user replaceable.
Either way, there is no point in sending it back to Apple - the machine does work perfectly well with the original HD.
Oh dear! I assumed you'd appreciate that a call to either Apple or one of their Service Centers would give you the relevant info.
 
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