I just got a refurbished MBP in May. So far, I've had to send it back to have the logic board replaced. Since then, things have been stable for the most part, but I figured I'd run the Apple Hardware Test just to make sure. When I run the brief test, it checks out. But when I run the extended test, it makes it to around 7 minutes of so and then the screen starts this godawful flickering and flashing at a really rapid rate. The AHT gets stalled, I can't shut it down, and I have to restart the computer with the power button. I've run independent tests with Tech Tool and Rember and they check out. Any ideas on why the AHT is causing the screen to flicker/freeze and generally go nuts? Do I have a lemon MacBook Pro?