Skip to main content

Model A1311 / Late 2009 / 3.06 or 3.33 GHz Core 2 Duo processor

309 Questions View all

What is the deal with the specificity of the HDD this rig will accept

So I just had my CPU card fixed, and installed it, along with another HDD. The one it came with was a Seagate ST31000528AS 9SL154-040 .

I know that there is discussion about compatibility of HDDs in this machine, but do not fully understand it.

After some reading up I concluded that it came down to the temp sensor connector being very specific on the A1311. Since I could not find the exact same Seagate, I tried a fully operational Hitachi Deskstar 7K100 1TB 7200 rpm Internal SATA 3.5 Hard Drive HDS721010KLA330, which I still had in my box of parts.

I dealt with the temp sensor by shorting it, to prevent it from spinning full tilt, and then installed Mac fan control and set the HDD to 2500rpm.

I fresh install of OS 10.6.8 on the new drive and all was well.

Next day, for reason beyond my comprehension, it suddenly does not recognize the HDD!! WTF?

My question is : What makes the EMC2308 so HDD fussy? Is there some firmware interfering with my choice of HDD?

Any light on the issue would be, as usual, eternally appreciated....Cheers, J

Answered! View the answer I have this problem too

Is this a good question?

Score 0
3 Comments

OK, after following your links I have got it. I do need the sensor upgrade kit so the logic board can communicate with the HDD and understand its language. Thank you so much, Dan. You, as usually, rock.

by

@danj , I am not sure what you mean with your comment: " You may need to replace the PRAM battery as the Startup Drive setting might be getting lost." Would you please inform me about the relationship of the battery and the PRAM. I am foggy on this, to say the least...

by

The PRAM (NVRAM) holds settings like what disk is the boot drive as well as the date & time. The PRAM battery gives the PRAM the needed power to hold this info when power is lost (vampire voltage).

Here's the IFIXIT guide to get to it: iMac Intel 21.5" EMC 2308 PRAM Battery Replacement

by

Add a comment

1 Answer

Chosen Solution

You are facing two issues!

Your system is only a SATA II (3.0 Gb/s) iMac 21.5" 3.33 GHz Core 2 Duo (Late 2009)

You need to make sure the drive is able to run at SATA II. I tried checking your drives specs I hope this is your drive: HGST DeskStar 7K1000 HDS721010KLA330 if it is your good!

As far as the sensor I would recommend you install either this unit: OWC In-line Digital Thermal Sensor for iMac Late 2009 - Mid 2010 Hard Drive Upgrade This will work with any drive! Or you can get the proper sensor part:

  • Hitachi - Apple P/N 922-9215
  • Seagate - Apple P/N 922-9216
  • Western Digital - Apple P/N 922-9217

The rub here is not all of the newer drives have the header which to plug in the cable.

As to using software to over-ride SMC, I'm not a lover. I've seen too many systems with blown fan's and/or dead logic board from over-heating. I strongly recommend going with the proper sensor setup.

Beyond these issues you should be fine. You may need to replace the PRAM battery as the Startup Drive setting might be getting lost.

Was this answer helpful?

Score 2
Add a comment

Add your answer

Jurgen will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 0

All Time: 113