I just upgraded the RAM in my MacBook Pro (15" 2 GHz Intel Core i7 - early 2011 model) from two 2gb modules to two 4gb modules. Started up just fine and ran great for about 10 minutes. Then the screen froze and the computer started beeping. After some google searches I found that it is caused by either a) bad RAM or b) the RAM is inserted incorrectly. My guess is that the computer shouldn't start if it's bad RAM. Others online report their computers beeping on startup. I tried repositioning the RAM to make sure it's in tight. The same thing happened.

The computer recognizes the RAM - it shows up in About My Mac. The RAM is Corsair 8gb 1333 MHz DDR3.

What's going on?

7 Answers 7


How many beeps are you hearing. A discussion thread on Apple's site suggests that 3 beeps is a sign of a bad memory bank. So maybe the connection is solid enough to display in About this Mac but "loose" enough for the MBP to see properly use the RAM? Trying to think of a better way to phrase that last bit.

  • I am hearing three beeps. I hope that's the answer because I don't want to have to return the RAM. But, I did open the computer and reposition the RAM very firmly in the slots, to no avail.
    – ethayne
    Oct 31, 2012 at 14:06
  • Is there a plate over where you install the RAM? My father had something similar on his iMac: three beeps after installing RAM. In that case, the plate wasn't screwed on tightly enough or maybe it was slightly misaligned. Oct 31, 2012 at 17:50
  • No, the modules are exposed.
    – ethayne
    Oct 31, 2012 at 22:07
  • Could there be some dust or particles where the RAM sits? Might be worth pulling out the chips and blasting it with some compressed air? Nov 1, 2012 at 21:56
  • Possibly, but I put the original RAM back in and everything works just fine. I think the RAM must be bad.
    – ethayne
    Nov 1, 2012 at 23:39

I have experienced a similar problem and sent my memory modules back in to crucial to get replaced.

The memory worked fine for a while but then I had it happen again to me last week.

I have a mid 2012 macbook pro with i5 and integrated graphics. I also have my computer hooked up to a monitor through the mini display port.

I have found that when I have mac hooked to monitor and either sleep or shut down while it is connected to the monitor and unhook it and try to power it up I will get the beeps. The only way to fix this is to open computer and remove memory modules and then reboot. Its something to do with the mac handling of the memory when attached to a different display, and then trying to power up the computer without the display attached anymore. The computer still thinks it is attached to screen and when I try to power up from the laptop display the computer does not know how to start.

I have fixed this problem by:

  1. opening the laptop while still attached to monitor
  2. disconnecting the mini display cable from the mac
  3. powering down the computer from laptop display

This has solved my memory beep problem. It might be helpful to try a purge of your memory in case the OSX is having problems handling the off market memory modules. Open terminal, type into terminal, "sudo purge", and then it will ask you to enter your admin password. This will clear out the processes that might be stuck in your memory. However, OSX should be able to do this on its own.

If your computer is running and the screen starts changing colors or just freezes and you have to do a force restart (followed by memory beeps) you will need to go to crucial website and do a warranty exchange. All RAM has a lifetime limited warranty. You can complete an online return RMA at: crucial.com

Hope this helps


I had the same three beeps with my Early 2008 iMac when I tried to go from 2 to 4 RAM. Making sure the door that you had to screw off to access the RAM is very tightly screwed back in fixed it for me.


I'm sure there is an Apple support page about the beeps, each of which means something, they're not to be ignored. But I wouldn't be so sure about your assumptions--my guess is, you've got bad/questionable RAM. Or, alternately, more RAM than the machine specifies--or a kind whose specs are slightly off.

You could try one chip at a time, also switching slots.

  • Thanks. I may try that. I did some research beforehand and I bought RAM that was recommended specifically for my computer, and the computer supports up to 8gb, so I don't think that's the problem.
    – ethayne
    Oct 31, 2012 at 14:15

i also installed corsair memory into a early 2011 Mac Pro.ran for 10 minutes and began beeping 3 x.i removed it and ran 1 slot with no problems for a day. switched postions and added the other one. ran 12 hours under heavy applications,then crashed. it corrupts my aperture files i won't do it it again waiting to here from corsair .i'm afraid i'll be eating the memory though.


Three tones in a series that repeats is universally a "Memory Problem" detected during power-on-self-test (POST).

Here are two support articles covering the general test and iMac codes (which match most recent Mac model POST firmware.


I have also experienced this problem with my iMac. There was a simple way I was able to fix it in the end.

All I had to do was switch around the different memory boards into different slots. For some bizarre reason once I had the 'right' card and slot combination the computer switched on and has worked fine ever since!

Hope this helps some of you out there if you are panicking as much as I was about your hardware.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .