It should be a memory contact issue. Booting the laptop while pressing on the memory modules will help. The problem is the motherboards in a few of the VGN series will flex over time. The only solid fix is to replace the motherboard (too expensive to be cost-effective). Try taping a piece of foam or rubber band to the memory cover for a temporary fix. From my experience, after it boots with video, you're fine until the next boot (or resuming from hibernate).