Is distorted display due to cable, LCD panel, video driver, or other?
• Onset of the problem was instantaneous and occurred while I was simply looking at the display, without touching the computer.
• The display shows normal and distorted colors at the same time: in some places bright green exchanged for black, purple for white, etc. Color positions don't change unless a window is opened or the window/menu arrangement changes.
• Windows are continually surrounded by "splash rings," similar to what you see when you open a widget in Dashboard, but frozen in one state.
• Strangely, I can sometimes see the (color-distorted) contents of one window showing through the background of another window that's in front of it, even though those same contents cannot be seen while observing through Screen Sharing.
• Faint "dancing" horizontal lines are barely noticeable in the brighter parts of the display.
• Component colors seem to have their rasters displaced relative to one another, like a color comic strip that was not registered properly when printed.
Note that some text was visually edited out for privacy.
• Windows, menus, and backgrounds seen through Screen Sharing are all perfectly normal.
• I have not yet tried an external monitor -- hopefully I'll have one set up today.
Steps taken so far
• Reset PRAM -- no change.
• Reset PMU/NVRAM -- no change.
• Booted from separate system on external drive (to detect possible corrupt system color table or other system software problem) -- no change.
• Shined light through Apple logo with the internal backlight lamp turned off. I noticed same color distortion problem (so it seems that the backlight is not the problem).
Having read other trouble reports here related to displays, I suspect that the display cable is the most likely problem, though I am concerned that the problem might actually be with the logic board or other circuitry that drives the display.
Finally, my questions...
• Should I replace the display cable?
• If not, what else should I do, and why?
• If so, what tips might you offer for best success?
Thank you for your time, interest, and help in solving this problem!!
Questa è una buona domanda?