I am planning to take my MacBook to the Apple Store tomorrow for the flickering screen issue I'm having. Today, I went and changed the RAM in my MacBook from third-party 2 GB sticks to the 512 MB stick that came with the machine. Once I finished that, I wrapped things up, opened the MacBook and hit the power button... Nothing. No power light, no sound, no nothing. Tried plugging in the power adapter, it lights up, so the battery is fine, but the power button does nothing. I tried switching back the RAM to the 2 GB that worked just a few minutes ago. Same thing. Power button does zilch. My MacBook is now completely dead. What could have been the cause? There's no flashing power light (they normally flash if no RAM is detected). There's just nothing. I'm taking it to the Apple Store tomorrow nonetheless, now instead of being about the flickering screen, it's now about a completely dead MacBook. It's easier to prove, I suppose.