Hey folks,
As the title says, I have a Dell Latitude E6500. Fresh install of Windows 8.1 with nothing on it except OS patches, and if I leave it alone long enough for it to go into sleep mode or for the screensaver to come up, the screen goes nuts. I get a screen full of squares that blink; some have a repeating pattern that looks like the corner of an old 8-bit icon of some kind. Squares are maybe just under a cm in diameter, multicolored in a limited range of colors.
Nothing in the system logs or any other logs. All memory and hard drive diagnostic tests come back clean.
The cooling appears to be working - I pulled the back case off and the fan was running, and it's not hot to the touch, so I'm thinking it's not a an overheating issue. It's a standard build with no modifications.
When I tap at the keys while it's got the pattern up, I can sort of make the pattern change, as though it's changing the desktop behind it, then if I hit escape it reverts to the previous pattern. It's stuck inside the pattern though, nothing gets it out. Have tried ctrl-alt-delete, escape, enter, space, moving the mouse, etc - nothing. I'm thinking that the issue is purely video and that the OS continues running fine in the background while this is happening, because once (just once and I don't know what I did to duplicate it) it came back from the crazy-quilt screen and I got my desktop back without issue. It's happened half a dozen times though, and mostly, no keyset I push will wake it out of the blinking screen.
The video diagnostics which run when you select diagnostics at the bootup with F12 come up good, all the lines display without issue. I ran the Ctrl-D video test on bootup and got a screen that displayed various shades of black at a steadily changing interval, but no beeps, and no actual video test shows up on screen.
The research I've done seems to indicate either a video card or a display inverter issue. I'm leaning towards video card because the video actually has no issues coming up when the OS first runs, or when I bring up the BIOS. Anyone have any thoughts?