9524 Views 8 Replies Latest reply: Dec 18, 2010 8:58 PM by minnepicker
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The bracket is the easy part, they also have specialized provisions for monitoring and controlling the HD fan depending on which Hard Drive is installed at the factory. In the 2009 and 10 models the temperature sensor is built into the Hard Drive and if you change drives or disconnect the sensor the Hard Drive fan will run uncontrolled.
See > [Aluminum iMac Q&A - August 13, 2010|http://www.everymac.com/systems/apple/imac/imac-aluminum-faq/imac-intel-al uminum-how-to-upgrade-hard-drive.html]
The following paragraph, sites problem better than I can...
+Site sponsor OWC also discovered that the "Late 2009" -- and subsequently introduced "Mid-2010" -- models use a "connector that seems to use the drive's internal sensors" rather than an external sensor like earlier Aluminum iMac models. This means that the only way to upgrade the hard drive is to "replace the drive with another model from the same manufacturer that [OWC or another third-party has] confirmed works properly with this thermal sensor cable". OWC provides a list of compatible drives. Readers have reported that taping an external temperature sensor to a hard drive or SSD that does not have an internal sensor will work, but this certainly could be risky.+
Here is more info from > [OWC|http://blog.macsales.com/2751-proprietary-cable-can-put-the-brakes-on-upgr ading-late-09-imacs]
OWC's response seems totally deceptive. The temp sensor issue is only a problem IF you replace your hard drive with a SSD, not if you install it via Apple's bracket and cable (which can be ordered from a variety of online vendors). Still, the Hard Drive Sensor Cable isn't that hard to work around. All one has to do is remove the cable entirely and replace it with Apple's Hard Drive Temp Sensor Jumper (this plugs directly onto the logic board), which effectively shorts the circuit and turns off the Hard Drive fan. This is how Apple does it on factory SSD installs. So OWC's comments seem to me to be "much ado about nothing."
I should clarify, by using the HDD Temp Sensor Jumper you're not actually shorting out the HDD fan completely - but rather shorting it to factory defaults, which means the HDD fan runs at about 1100 rpm or so, the same as it does on any standard hard drive install. The jumper essentially tricks the logic board into believing that a normal HDD is present and the fan runs at optimum speeds for normal cooling (and no SSD is ever going to get hotter than what is required by that!).
And to answer your question, no, you're not putting any other components at risk - this is exactly how Apple does it at the factory.
It looks like you have a late 2009 27" iMAC and a Mid 2010 as well, so you might have experience to answer my question.
I have a late 2009 27" iMAC and would like to ADD an SSD for OS and Apps only then utilize the existing internal HD for data only. After reading through several threads, it's not clear if an SSD will fit and connect with the late 2009 models. I see plenty of references to Mid 2010 models.
Have you been into both machines? Can an SSD be ADDED to my late 2009 model? Is there physical space? Do the late 2009 models have the correct cable connections?