Upon waking after being asleep for several days My June 2006 MBP 17 came up with a very low contrast(dark), negative, noisy display. I initailly thought it was just cmd-opt-ctrl-8. While that fixed the negative problem, that was not the issue as an external display is negative while the built-in display is positive and vice-versa. External display(VGA) is also free of all issues.

In addition to the negativitiy, the display is very low contrast and dark. it is basically impossible to make anything except bright colors and black text on white. it is almost as if the color depth is set to 256 color with the brightness very low, but all display settings are normal. There is also noise on the screen that rolls from left to right and the display flickers from top to bottom very quickly, almost like a CRT at 60hz. I have tried cmd-opt-p-r on boot with no effect. These problems are present at boot and on windows XP as well.

The only cause I can think of is could be related to opening the machine when I installed a new hard drive, although that was several weeks before the issue appeared.

is this likely to be lcd panel, or logic board trouble? I have found other discussions online for other PC laptops (no macs) but no resolution.

That is generally going to be the logic board since both the main display and external display is affected. You can try resetting the firmware by holding down Apple-Option-P-R during bootup or reset open firmware if that doesn't work which you hold down Apple-Option-O-F then type in the following

reset-nvram
set-defaults
reset-all

The machine should then reboot and see if it is fixed. If that doesn't fix it, I would try booting up from your install disk and see if that works normally, this could tell you if it is possibly a software problem.