Hard drive fan runs full speed after installing after market hard drive in Imac 20.5" late 2009

We need to know more about the computer you have in order to help. The reason for this is some iMac's must use HD's with a temp sensor integrated into the drive in order for the system to work correctly.

You issue could be as simple as doing a SMC reset or as complex as replacing the drive you bought with one designed for your iMac or anywhere in between. Without knowing at least which model you own we cannot give you much advice though.

Roger

Beginning in late 2009 Apple began using HD's that had the heat sensor integrated into it, if you are absolutely positive your replacement drive has an integrated sensor in it then your problem might be solved by doing a SMC reset. If you haven't done one before here are the instructions:

SMC RESET

• Shut down the computer.

• Unplug the computer's power cord and all peripherals.

• Press and hold the power button for 5 seconds.

• Release the power button.

• Attach the computers power cable.

• Press the power button to turn on the computer.

PRAM RESET

• Shut down the computer.

• Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.

• Turn on the computer.

• Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.

• Hold the keys down until the computer restarts and you hear the startup sound for the second time.
• Release the keys.

The October 2009 iMac and later models require Apple-branded hard drives with custom firmware. The custom firmware changes the function of the jumper block normally used for speed selection. With Apple's firmware this is instead used for reading the temperature of the drive.

To install a non-Apple hard drive, the new temperature sensor cable needs to be replaced with the older cable that measures the temperature externally. The cable P/N is 922-9229 and can be ordered online from a few sources. I ordered mine from MacPartsOnline.com.

Is there no way to get the Apple firmware?

Is there some email address I can send a request to?

I replaced my original Seagate drive, ST31000528AS with a new equivalent (I thought) Seagate drive ST31000524AS. Anyone know if any new iMacs come with this drive, and therefore if there must exist a new firmware for this exact drive?

For the moment I'm manually controlling the fan speed with a free app, but my only long term alternatives seem to be to pay for a program that monitors the temp via the SMART interface, or buy an external temp sensor.

I have a Widget that shows things like HD temp, which I was curious about as it seems to show a real temp (in a resonable range, goes up and down) which doesn't make any sense if the HD sensor is not working. But I realise now that this too must use SMART rather than the actual temp from the sensor.

The_Mighty_Boosh wrote:

Is there no way to get the Apple firmware?

Is there some email address I can send a request to?

IF your computer needs any firmware updates that will be found by running Software Update. If SU indicates no updates are needed, then no updates are needed. It's that simple!

I'm talking about the "special" Seagate HD firmware that Apple use to re-purpose the connector that is usually used to control the speed, but with the HD firmware update now reports the temperature.

Dumb question... Have you checked Seagate's support site?

I spent a while poking around there, but this line gives me the impresion I'm not going to find what I'm looking for on the Seagate site http://knowledge.seagate.com/articles/en_US/FAQ/206091en?language=en_US :

Some drives that still bear the Seagate name on the label but are actually the property of an Original Equipment Manufacturer (OEM) (such as Dell or Hewlett-Packard [HP]) might have unique firmware on them. OEMs purchase large amounts of bare drives from Seagate and put their own firmware on them, at which point the drive is sold as part of a larger piece of equipment, such as a server or a personal or notebook computer. Often the OEMs load specialized firmware in order to be able to build in performance enhancements that are specific to their product.

Agreed on the firmware. One thing i would suggest is contacting an AASP and ask how they handle HD upgrades on late 2009 and later iMacs. I suspect you will need to control it the fans via a fan app.

Old article, and someone here recently checked OWC for availability of compatible Seagate drives, who reported they have nothing. But maybe they have some idea about a firmware update, if that's even necessary for the late 2009s.

http://blog.macsales.com/2751-proprietary-cable-can-put-the-brakes-on-upgrading- late-09-imacs

For Tech Support

http://eshop.macsales.com/tech_center/

I thought I'd take my own advice and so I contacted OWC myself. According to what I was told -- something I already knew -- only the drives for the 2011 iMacs may require firmware updates (I have no idea if such firmware updates exist or, if they do, if they are even publicly available) and are completely Apple/OEM proprietary.

The '09-'10 iMacs, in order to use the original proprietary sensor cable, only require drives from the same manufacturer. The very experienced tech I spoke to told me that he has never heard of a case where a drive from the same manufacturer, Seagate or WD, didn't work properly in those models.

I know there have been some reported exceptions to this, which I can't explain.

I ended up using both an temperature sensor cable for optical drives AND smcFanControl after replacing the 500GB drive in my late 2009 iMac (21.5") with a 2TB WD . I found my iMac to become uncomfortably hot with the default slow fan speeds even before the hard drive upgrade. And the hard drive getting close to 60 degrees Celsius will probably shorten its lifetime. So with smcFanControl I upped the speeds to 2000 for optical and CPU and 3000 for the hard drive. With these speeds the hard drive remains below 50 degrees and the iMac fairly cool to the touch - with a very slight increase in fan noise.

WZZZ wrote:

The '09-'10 iMacs, in order to use the original proprietary sensor cable, only require drives from the same manufacturer. The very experienced tech I spoke to told me that he has never heard of a case where a drive from the same manufacturer, Seagate or WD, didn't work properly in those models.

This is not correct in my experience. AFAIK, Apple-branded drives have custom firmware. In my case, the 500GB Western Digital drive originally installed in my iMac has a jumper block normally used for SATA speed selection. The Apple-branded version of the same drive is using the same jumper block for reading internal drive temperature. Either get a sensor cable for optical drives and fix it to the drive body, or use a fan speed app.

abubasim66 wrote:

WZZZ wrote:

The '09-'10 iMacs, in order to use the original proprietary sensor cable, only require drives from the same manufacturer. The very experienced tech I spoke to told me that he has never heard of a case where a drive from the same manufacturer, Seagate or WD, didn't work properly in those models.

This is not correct in my experience. AFAIK, Apple-branded drives have custom firmware. In my case, the 500GB Western Digital drive originally installed in my iMac has a jumper block normally used for SATA speed selection. The Apple-branded version of the same drive is using the same jumper block for reading internal drive temperature. Either get a sensor cable for optical drives and fix it to the drive body, or use a fan speed app.

This is interesting. If this is so, since it's "custom firmware," one would have to rely on one of the workarounds. I will have to look further into this.

What then do you make of OWC's report on this from '09?

Fortunately, you can reuse the cable that came with your iMac as long as you replace the drive with another model from the same manufacturer we have confirmed works properly with this thermal sensor cable. To determine what brand hard drive your iMac has, go to About This Mac, click on Serial-ATA, and then look for the drive model installed at the factory. If the model has the preface WD, that’s a Western Digital hard drive and if your drive has a ST, that’s a Seagate hard drive. Once you know what drive came with your Mac, you can upgrade to a larger drive and continue to use the thermal sensor…thus avoiding the “ear pleasing” whoosh of fans on high.

http://blog.macsales.com/2751-proprietary-cable-can-put-the-brakes-on-upgrading- late-09-imacs