I very recently got Acer TravelMate 5520 with Vista, AMD Athalon 64 X2 Dual-Core Processor TK-55 1.80 GHz, and 766 mb of RAM. Now, the thing is, the screen has blacked out on me twice (sound disappearing as well), and both times, no matter how long I waited, nothing happened, and I had to force it to shut down. When I start it up again it looks fine, but being a big novice when it comes to this sort of computer stuff, I don't know what I should check for faults. And I'd rather not let this keep happening. Help, please?