Ok, Ill add my 2 cents.
As seen in this pic...I suffer from the color problems as described by most of you guys before you get the black screen. I however never got the black screen, but instead had alot of strange colors like below.

Here is how I fixed it (I'm still experimenting, but its definately ALOT better than it was. Only had colors one time in a month and a half of pretty regular gaming, but as soon as I tightened the M5 bolts, colors went away. (Think its fixed/90% sure)
To fix it, I did RBJTech's M5 X-Clamp replacement. I also cleared all old paste and applied Artic Silver 5. I tightened down the bolts to a reasonable, but rather loose config. The fix immediately fixed all my colors for about a month and then they came back one night. I immediately opened the box, tightened the M5 bolts and the problem IMMEDIATELY disappeared and stayed away.Now as to what is causing my problem, I like the overheating theory and it kinda makes sense. When I did get colors that one time, I just kept playing. As I played the colors got worse and worse and worse. HOWEVER, people keep talking about OVENS. RBJTech also talks about stressed BGU pins, but I've never heard of BGU pins. I however HAVE heard about BGA Ball Grid Arrays. (
What is a Ball Grid Array)BGAs fasten down the GPU and CPU to the board. Its like lets put a couple dollops of solder on the board...set the chip down on those little solder balls.....and lets BAKE IT. Hence all the recent talk of Ovens. This is what I have made of it anyway.
Since I don't have an X-Ray machine or an Oven, I can't check the integrity of my BGA's under my GPU. However, you'd think that a tight M5 X-Clamp replacement would tighten the connection between the Chip and the BGA and the motherboard, to fix the problem. This might just be the problem too, and that is what is fixing it. I really don't know, but it seems my 360 is working. People suffering from the no video should at least try the M5 X-Clamp replacement method. It couldn't hurt. And from all the accounts I've read of (Prolly 10-15 now, People start off with colors like me...then progress to a black screen. I fixed my colors...so you'd think it would fix black screens too.
I'd be interested if there is a poor man's version of inspection BGA's and rebaking them without all the expensive equipment. Heat Gun method and reflows. Would a heat gun really be able to reflow th BGA under the GPU? I want to KNOW know what is causing this color bleeding/artifacts >>>> black screen problem.
Hmm. hacktek's report of overheating signs + no video, suggests this might be an overheating deal. I never got any red lights associated with my colors, but then I never got a black screen either. However, I do know that there is QUITE a connection between the colors and black screen as exampled by a couple of accounts on this forum. Another thing that is important.....as hacktek mentioned. When this color artifacting occurs.....users are not able to change their resolutions. They are tied together....if you are getting colors you won't be able to change your res either.