13" aluminum unibody, 2.0 or 2.4 GHz Core 2 Duo processor.

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MacBook freezes after RAM upgrade

Hello, Yesterday I upgraded my RAM from 2x 1GB sticks and added a 4gb RAM stick...so in total I have 5GB RAM.

When I click on 'about this mac' it shows up as 5GB RAM however sometimes it only shows up as 4.75GB or 4GB RAM- why am i losing a gig of RAM sometimes?

After the upgrade and I started to encounter problems. When I close the lid the macbook would restart by itself. Sometimes when I open the lid it just shows a black screen where I have no other option but to manually restart the macbook. What could I do to resolve this problem?

I have tried resetting the PRAM and the SMC, but no change.

Thanks, Michael.

Answered! View the answer I have this problem too

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I went into terminal to find out the wake reason...this is the code showing so I have copied it.

Michael-Sius-MacBook:~ michaelsiu$ syslog |grep -i "Wake reason"

Wed Jun 13 15:50:19 Michael-Sius-MacBook kernel[0] <Debug>: Wake reason = OHC1 EHC1

Wed Jun 13 15:50:28 Michael-Sius-MacBook kernel[0] <Debug>: Wake reason = OHC1 EHC1

Wed Jun 13 15:51:54 Michael-Sius-MacBook kernel[0] <Debug>: Wake reason = OHC1

"OHC: stands for Open Host Controller, is usually USB or Firewire. If you see OHC1 or OHC2 it is almost certainly an external USB keyboard or mouse that has woken up the machine."

I do not have anything external attached to it?

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Any further help anyone? Thank you

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My first thought is you may have the incorrect ram for your computer. According to MacTracker your computer should take 6 GB of ram- (PC3-8500). What did you install?

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Sorry but what does reseating the memory mean? I'm pretty sure I have got the correct RAM...I purchased this:

http://www.ebay.co.uk/itm/190662978861?_...

Strange how these problems have came up after installing the RAM...I have tried installing the original 1gb Ram stick, however this still had the problem of restarting by itself

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Seems to me one of the ram modules may be bad or may not like being mismatched.

Most important things to note when installing ram:

1) NEVER touch the pins on the chip with your fingers, always hold the modules by the sides of the wafer.

2) ALWAYS be wary of ESD, make sure you are grounded or at least not wearing socks on the carpet when opening your computer and accessing ram.

3) It's not necessary, but most ram problems come from mismatching chips. Most ram today is sold in dual channel, 2 module packages (6 gb max ram usually forgoes this), but Macs seem to prefer matched module sizes. That said, I've installed a 4gb module with a 2 gb module in a computer one generation older than the one you listed and had no trouble at all.

Re-seating the ram is merely popping the modules out of the socket, perhaps blowing out the socket with a can of compressed air, then re-installing them carefully and evenly, being sure they are flat, flush, and fully inserted into the socket. Perhaps try running the 4gb module by itself and see if the problem persists. It may be that one of the original modules was damaged during your installation and could be causing the problem as well.

Good luck and let us know what you find.

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Check the latency and timing of your ram also, the chip you installed may be a higher capacity but slower latency chip, and may not play nicely with the other chip you have installed.

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Thanks for all the info. The RAM i purchased is: http://www.ebay.co.uk/itm/190662978861?_... i bought this RAM brand new. It seems to be exactly the same RAM as the original ones installed.

I have tried just running the 4gb module by itself however the problem still occured, I have re-installed the extra 1gb ram so at the moment it is showing 5gb ram running. Any other solutions? I have read on other forums something about not being able to move the macbook after closing the lid until the flashing pulse light shows. I am running snow leopard and my software is upto date if that is any use.

Thanks for your help, really appreciated!

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Just to add I had the lid closed for about a minute and within that time the apple logo light on the lid would flicker on and off every 8 seconds.

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I have installed the original 2x 1GB modules and still having problems. When the apple lid logo flickers it doesn't seem to put the laptop to sleep which in a way is better than it randomly restarting

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Go with just the single 4gb chip. Try switching the slot it is installed in and see if that makes a difference.

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I have 8 GB of RAM in my Aluminum Macbook Unibody and it runs great. My guess is you have a bad stick.

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Any idea why my original ram is now having the same problem?

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Your Macbook probably has a different logic board/processor than Michael's. Core 2 Duo processors, to my knowledge, only accept up to 6gb in Macbook Pros. Your MBP must be a newer model.

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No mine is a 2008 Aluminum Macbook not a Macbook Pro Has a 2.0 C2D. Also can't you change what the Macbook does on lid close in system profiler?

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Mine is also the macbook aluminium 2008. I am not sure how to edit what the lid does on system profiler however

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Have you run Apples 'System Profiler' app to see what it reports about the memory you bought? You can get to the app via the 'About this Mac' menu choice under the Apple icon, then select 'more info' button. Slide down to the Memory listing and check your memory against your original memory it should have the same other than size.

Apple also released a quiet update to the EFI Firmware to address memory access issues (when using larger SIMM's) Using the Profiler App again check your firmware level when you click on the Hardware tab its self it should be MB71.0039.B0E If not go here Firmware Update 2.1

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System profiler shows up as ok. And i cant update the firmware as i dont have the right software. I am running snow leopard. thanks for the help

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Michael - Then use the older firmware - http://support.apple.com/kb/DL1332 as it too had the HD update.

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That firmware doesn't work either...the message says 'ALERT! This software is not supported on your system'

Do you think wiping my HD clean and freshly reinstalling snow leopard again will help with anything?

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Okay seems like nobody answered you to help reset PRAM or NVRAM since it's particularly the issue over RAM replacement.

Here's how?

  1. Shut down the computer.
  2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
  3. Turn on the computer.
  4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
  5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
  6. Release the keys.

Your computer's PRAM and the NVRAM are reset to the default values. If any PRAM or NVRAM congestion was causing such issue, it should have been addressed by this attempt. Cheers!

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Thanks..i have tried resetting this however no luck! Macbook still restarts when lid is shut...so annoying! any other tips? Thanks

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I'm so sorry to hear you are having such a genuine issue. It's pretty frustrating. Now, please remove the RAMs from the MacBook. Start your MacBook without RAMs in it. Shut down pressing the power button for a few seconds. Place the Memory sticks back again pushing all the way inside that could go. Don't hesitate pressing inside. Only pay attention not to touch the elements around the edges.

And then, here, I'm going to tell you something unusual but please follow it. Get the hairdryer. Please blow cold air into and around the fans and heat-sink. Blow it until every dirt flies off. Please start your MacBook. It should work normally now. Cheers!

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do not put a hair dryer anywhere near your mac. this is the stupidest piece of disinformation ive come across. this will solve nothing.

to clean the inside of mac, use compressed air or an air compressor on light settings.

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Hair dryers don't offer enough force within a narrow angle that you need, use compressed or can'ed air. Even still, a soft brush will be needed to loosen the dust.

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Michael will be eternally grateful.
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