MacBook Pro keeps freezing randomly Since about two weeks ago, my MacBook Pro started freezing randomly. If iTunes is open, for example, the music keeps playing, but both the keyboard and the trackpad are not responding and it only recovers with a hard restart. I also noticed that it happens (not always, but sometimes) when I move it.

It’s an early 15" 2011 MacBook Pro with the latest version of Mavericks; original RAM and HDD.

How can I diagnose this issue?

I already checked the disk from recovery mode and says it’s fine. I also read the related questions here, but they don’t really apply.
After countless trips to the Apple Store and extensive testing by them, it turned out I have faulty memory DIMMs. At least that’s the only plausible explanation they reached after some 8 days of testing.