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Macbook Pro Memory Woes
Sunday my Macbook Pro (Core 2 Duo) downloaded a software update and wanted to reboot, so I said “OK.” When it started back up, I got three beeps and then the power light flashed. Obviously it didn’t boot—it had failed the power on self test with a RAM error. Not good.
I tried reseating the memory, no joy. Finally, I discovered that I could put either SIMM into the top slot and it would boot, but putting anything in the bottom slot failed. So, I booted with just the 2Gb card and made a clone of the machine to another Macbook Pro I had sitting around. Whew!
The next morning I put both cards in with the intent of taking it in for repairs, but it booted fine. I swapped them. It booted fine, but only showed 1Gb of RAM. I rebooted and saw all of memory.
I decided to try the Apple Hardware diagnostics (boot with the OS disk that came with your machine while holding down the “D” key). No problems found. I thought maybe it was a heat issue, so I downloaded something to exercise the CPU and get the heat up. Still, it boots fine.
At this point, I’ve got a machine that seems to work that I don’t trust. Argh! Any ideas?
Posted by windley on April 24, 2007 10:27 AM
Comment from Jesse Harris at April 24, 2007 11:54 AM
There's an OSX port of the venerable memtest86 utility for running tests on RAM. If it's bad, this utility can and will expose it. Linkage: http://www.memtestosx.org/
Comment from kevin at September 24, 2007 10:59 PM
This nearly identical incident just happened to my MBP after an iTunes update with one other package, I admit I forgot what that one was already. I too am able to boot afterwards, however I get no GUI. I have my booting set to verbose as default, and I just end up with a shell, with network running.
After I ran the s/w update, I opened iTunes- it crashed. I tried another app, it too crashed. I tried a bunch of other apps- most crashed, but Carbon based apps did not. I tailed my system.log when I started an application, and I got this: UserNotificationCenter crashed
Each crashing application generated that. Well, end of the day, time to go home and I put the system to sleep. Later when I woke it up, the login screen crashed again and again. Ok, let's restart. LOUD beep- followed by 3 short beeps and a grey screen. Uh oh. Not good. Again and again, same deal. After seeing how 3 beeps is generally a memory error I popped the modules out and put them back in. Nada. I then found your post, and then tried it with one module. Well, it started this time, albeit, in it's hobbled state. I could at least scp my logs to another system in order go through before my call to Apple.
Not very happy about this, but was glad to find I am not alone. I could find no other similar description.
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