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

I notice that that is an old article and the drives it links to (the Seagate 1TB at least) is no longer available. It may be that the older drive's firmware output temperature values to the connector, but the newer ones don't.

You could try HDD Fan Control (http://www.hddfancontrol.com/).

This will vary the speed of the fan according to temperature, but it is £19.02 (curious price). It uses SMART to get temp data, and I can confirm from the 1 hour free trial it does seem to work.

One thing to note though is that you will have to uninstall it after the free trial in order to be able to control the fans again with smcFanControl. Otherwise the fan speed changes for about a second before returning to the previous speed.

I've not purchased it yet myself, because I am still looking for a HW fix where I don't have to run another background task, but this may be the simplest solution, and probably cheaper when you take into account the cost of an external heat sensor cable, and the hassle of taking the iMac apart again...

The_Mighty_Boosh wrote:

I notice that that is an old article and the drives it links to (the Seagate 1TB at least) is no longer available. It may be that the older drive's firmware output temperature values to the connector, but the newer ones don't.

The age of the article should really be irrelevant. BTW, there is the free SSD Fan Control, which may be eqivalent. Might be a good idea to check out reviews, if any, for it before installing. Search for "exirion.net"

http://exirion.net/ssdfanctrl/

A correction to my own post. The original drive installed in my late 2009 21.5" iMac was a 500GB Seagate drive. Here is a thread where I talked about this last year: https://discussions.apple.com/thread/3077734?start=0&tstart=0

And FYI: I have been using a 2TB drive in my iMac for almost a year now. No problems at all using the optical drive sensor cable with it.

Thanks for the tip WZZZ. I'll give that app a try, but it looks like it only sets a fixed fan speed that doesn't vary with the HD temp as HDD Fan Control seems to do.

Still it sounds easier to use than setting up a startup script for smcFanControl, especially if it works when the Mac comes out of sleep, which my current way of doing it doesn't.

As for the age of the article, I only meant that the drives they were talking about at the time (3 years ago) might have been compatible, but the drives that are available now don't seem to be. The proof being that my new Seagate drive is not giving out the correct temp signals via the cable.

A thought has just occured to me.

I'm worried about setting a fixed fan speed for my HD because the temp can vary quite a bit. Of course it does, it gets a lot of use.

BUT, I hardly ever use my optical drive.

If I could set a fixed fan speed on that, and repurpose the temp sensor for the HD, all my problems might be solved!

Looks like OWC maybe doesn't know what they're talking about. The guy was adamant that any drive from the same manufacturer works, so I don't now what that's all about. Maybe the WDs are different, but I wouldn't bet on it.

This looks like the best workaround. This is for the 27", but it's the same idea. Of course, it means opening the computer up again, and I imagine each time you do that the chances of damaging a cable or the EMI shield increase. Thanks Apple for the PITA. (I'm dreading the day when the PRAM battery -- a basic CR2032 button battery -- needs replacing in mine. It's buried so deeply it requires 35 steps and you keep going even after the logic board is removed. When the time comes I'll probably give it to an AASP for $150 labor. Completely ridiculous for changing a $5 battery.)

http://www.digitalintrovert.com/2011/09/03/how-to-upgrade-hard-drive-late-2009-2 7-imac/

http://www.macpartsonline.com/922-9214-optical-temp-sensor-cable-21-5-inch-3-06- 3-33ghz-imac-late-2009-a1311.html

I'm assuming the sensor is included with the cable. Kind of pricey. Maybe someone else has it for less. Here's one.

https://www.usedmac.com/products/922-9214-imac-215-intel-optical-temp-sensor-cab le-late-2009

KIND OF PRICEY!

That is more than I paid for a whole replacement optical drive (I guess this is why the sensor didn't come with it).

What a massive rip off!

I'm a coder, not an electronics engineer, but I would be very surprised if this cost more then £1 to produce.

What a shame people are so greedy.

SSD Fan Control can use the SMART data on the hard drive to control fan speed. In fact you can choose three options for controlling the speed AUTO which uses the Apple Sensor cable (no good if you've changed the HDD obviously) MANUAL where you can set a fixed speed or SMART which is probably more accurate than Apple's sh!tty method. Please support the developers if you can afford something because all other alternatives are such a rip off. HDD Fan Control costs the same as Mountain Lion - which is ridiculous profiteering and I'd love to see SSD Fan Control kill it off.

Why are you posting on a 6 month old thread?

Why not?

I see I had already mentioned SSD Fan Control a few posts back.

Yes WZZZ you did and thanks very much for that but The Mighty Boosh replied "I'll give that app a try, but it looks like it only sets a fixed fan speed that doesn't vary with the HD temp as HDD Fan Control seems to do."

So I just wanted to set the record straight, because the new version of SSD Control does have SMART temp control, NOT just a fixed speed. And it's free!

🙂

That's good to know. Does that mean it's now equivalent to HDD Fan Control?