Late 2009 i5 iMac 11,1 32GB RAM upgrade problem

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Level 1

4 points

Late 2009 i5 iMac 11,1 32GB RAM upgrade problem

Having read that the late 2009 27" 2.66GHz i5 iMac 11,1 can handle 32GB I purchased 2 sets of Mushkin Apple 16GB (2x 8GB Kit) PC3-8500 Unbuffered 204-pin SO-DIMM - for a total of 32GB.

Installed OK and showed 32GB as expected yesterday, however the next day it is only showing 16GB.

2 slots are showing empty & 2 slots correctly showing 8GB modules.

I've checked the seating of the RAM and made sure it is OK.

I've zapped the PRAM and still only 16GB shows up as installed.

Any ideas ?

iMac, OS X El Capitan (10.11.5)

Posted on May 26, 2016 8:54 PM

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Answer 1

babowa

Level 9

78,606 points

May 26, 2016 9:41 PM in response to Jack.Russell

Not sure if this would apply since I don't know which OS you are running (check the section under RAM) - found the info.........

http://www.everymac.com/systems/apple/imac/specs/imac-core-i5-2.66-27-inch-alumi num-late-2009-specs.html

And, the two most recommended RAM vendors here are macsales.com and Crucial; other brands may or may not be the exact specs, latency, etc. that finicky iMacs need.

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Answer 2

Jack.Russell Author

Level 1

4 points

May 28, 2016 1:45 PM in response to babowa

Hi Babowa,

https://www.ramcity.com.au/buy/mushkin-apple-16gb-2x-8gb-kit-pc3-8500-unbuffered /2x972019A~KIN1-Ai)-00-1570

Certified Apple RAM so the CAS timing etc should be in spec.

The issue is that when I installed it and restarted the 32GB showed in the activity monitor, the next day - after shutting down overnight - only 16GB shows in the activity monitor and only 2 of the 4 memory slots show as being occupied.

Wondering if anyone else has experienced similar or has any suggestions - apart from swapping modules around, which is what I am about to try.

Cheers,

Jack.Russell

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Answer 3

Old Toad

Level 10

217,004 points

May 28, 2016 2:08 PM in response to Jack.Russell

Remove the RAM modules and put the original Apple modules back in. If all is well then the 3rd party modules that you bought are not compatible.

Return the RAM modules and replace them with modules from Crucial.com or otherworldcomputing.com.

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