RAM not recognized

Question

Level 1

4 points

RAM not recognized

Back in February I upgraded my late 2009 27 inch 2.66GHz intel core i5 iMac with 16MB ram, 4X4GB modules. Everything was fine. Yesterday I noticed that only 8GB were being recognized. Two on one side were fine and the two on the other side were not being recognized. I removed all the modules and switched each pair from one side to the other. That worked.

This morning I again only had 8GB recognized. The pair of modules recognized were now on the opposite side. I reset the NVRAM/PRAM and I again have 16 MB or RAM. Any ideas as to what is going on would be appreciated.

Thanks

iMac, OS X Yosemite (10.10.2)

Posted on Aug 31, 2015 11:03 AM

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Answer 1

Best reply

rkaufmann87

Level 10

140,532 points

Sep 8, 2015 9:56 PM in response to Kent623

Try restarting the computer and re-check. You can also verify the RAM in the System Information app already installed on your system. Pleas post back with your results.

If neither of the above work, the new RAM may be have become unseated, remove and reinstall to test. It might have also failed, if so return and purchase Crucial or OWC (www.macsales.com) .

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Answer 2

Ralph9430

Level 7

21,732 points

Aug 31, 2015 2:32 PM in response to Kent623

Either the RAM is not compatible with your Mac, it is bad, it is not seated correctly or there is a problem with the socket.

Reseat the RAM and restart.

Try the good modules on all sockets to make sure all sockets are good.

If you continue to have problems contact the store where you purchased the RAM and ask for a replacement.

Crucial and Other World Computing are the best places to purchase RAM for Macs.

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Answer 3

Kent623 Author

Level 1

4 points

Sep 8, 2015 10:02 PM in response to Kent623

Thanks for the responses. I do have the correct ram for my computer and all the modules were correctly seated. I took all the modules out and replaced them one at a time in the same slot. 3 of them worked as advertised but the 4th one left me with a dark screen and a periodic beep which I found out means there is a problem with the ram. Have returned the defective ram to Crucial and am waiting for a replacement and my computer is running just fine on 12GB ram.

Again thanks for the help

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Answer 4

rkaufmann87

Level 10

140,532 points

Sep 8, 2015 11:08 PM in response to Kent623

Your welcome.

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