Hi, Yesterday when I got back home, I took my mid-06 MacBook out of my backpack and lifted the lid and it didn't come out of sleep. After a while I simply did a hard shut down and my computer refused to function. It would turn on: I could hear the fan and the sleep light would turn on. But tthat's alll. After some freaking out, I got the disc that came with my MacBook (a tiger install disc, couldn't find my leopard disc) and inserted it- hallelujah! It booted into the disc and I verified the disk. All was fine. I rebooted back into leopard and all seemed fine till... Moving my computer in the slightest causes it to restart. After a while of this, it reverted back to not functioning so I reinserted the tiger disc and it still does not work. So now I have a MacBook that can't get passed a black boot screen with a copy of tiger stuck inside I tried the steps in apples troubleshooting guide: troubleshootng computer with no video. Still no luck. Anyone have any advice to fix this or shall I just take it into warranty to get serviced Thanks to those who reply.