about a week ago I was watching some video's on youtube, when all of a sudden my mac froze. a simple reset and the computer started booting fine but as soon as it got the the part where it starts to load the os it just stopped on that kinda blank blueish screen. restarted a few more times and the same thing. so I then tried to boot off of a external firewire drive with leopard loaded on it and it still did the same thing. I then gave up for about 30 min tried again and it did work but froze about 15 min later. so then I completely re-installed the os and after reboot it went to the same blueish screen. at that point I thought it may be a heat related problem. so letting it cool over night I can use the computer for about 15 min before it freezes. putting the laptop in the fridge for about 30 min I can get about an hour out of it. the computer doesn't see to be getting hot at all. nor am I straining it that much. the fan is not coming on and its really only come on a few times in the computers life when I'm really working it. this thing has been good to me for almost 4 years now except a keyboard which was covered by apple care. Any thoughts on why its doing this? worth fixing? or should I just accept the computers death