Ok, so about a week or so ago my computer has started to go in and out during the boot process. When I say go in and out I am talking about the monitor, It has signal, then it doesn't, then it does, then it doesn't. Once I would get into Vista though everything seemed to be fine.
I thought that my 4870 HD was going bad but I borrowed a 260 from a friend of mine and when I installed it, It booted up and worked. I turned the computer off to go to sleep and now when it turns on the screen shows the boot process up to the point where the vista bar that would show the OS loading is supposed to appear.
At this point in the process, the signal to the monitor is lost. I know the computer is working because If I listen to the speakers I can tell when I am at the login screen and then I can login and you can hear skype and stuff starting up.
A related issue, when I tried to turn on the computer with my 4870 the screen would flash from a black to a lit up black screen (black on a lcd is bright) with a corner that had remnants of the vista start up bar. It looks torn though and is only a small portion of hte bottom left corner that has this artifact image.
The monitor would flicker between black and the artifact image forever.
The computer has performed perfectly for the past 3 months I have had it, just started with these problem now.