MacBook Pro Special Report: Repeated system freezes or sudden restarts -- Checking for bad RAM

CNET staff

Sept. 2, 2009 7:13 a.m. PT

3 min read

Some MacBook Pros suddenly restart during routine operation or exhibited repeated, inexplicable freezes.

MacFixIt reader Brian May writes:

I'm on a Brand new MacBook pro 1.83 GHz with 1.5 GB RAM. Mac OS X 10.4.6 (and my firmware is up-to-date). My problem : I've got unwanted reboot every day. The first time this arrived was when I was watching an .avi film with VLC. After the reboot (I didn't ask but came as the image of the .avi film was freezing), I launched the film again and had no problem till the end. Next time, this unwanted reboot came with Popcorn. And this either with my internal superdrive or an external one.

'At the same time, when I leave my MacBook pro alone and go help someone on site in my office, often, when I come back to my desk, my computer has rebooted (the session window is waiting for my password...) : this two or three times a day."

In some users' cases, the problem is bad RAM.

One reader writes:

"I have a week 7, 2.0GHz MacBook Pro that I ordered with 2 GB of RAM. I was experiencing random reboots, kernel panics, application crashes and failed application startups.

"I ran the extended hardware tests off the special 'D' partition of install DVD #1, and it told me there was a memory problem. After removing one SODIMM, the tests succeeded. After swapping the SODIMMs (still only one in), the test failed.

"I ordered a replacement SODIMM from Apple, popped it in, and haven't experienced any random reboots or other such issues since.'"

If you are experiencing similar issues, try running the Apple Hardware Test. Insert the Mac OS X installation disc in your Mac, then restart while holding the D key. Run the appropriate tests.

if an error occurs (or even if one doesn't if you'd like to be sure), try removing one, then rebooting and checking for persistence of the problem. Then remove the other one (replacing the first removed module), restart and check for persistence of the issue, i.e. test for bad RAM by leaving only one module in the unit at a time.

If one of the modules is bad, contact Apple or the appropriate vendor for a replacement.

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