If the symptom you describe is being caused within the display, one reason could be a weak CCFL backlight tube. If the tube fails to fire up correctly, it can produce a dull reddish light output. And this can become more frequent as the tube gets weaker over time. If you are content to follow the instructions you've referred to regarding panel replacement, and open up the casing, you might be lucky and find the panel has somewhere the backlight is visible from behind, so you can see whether the light output is still white during the faulty operation, or if it's gone duller red. That would tell for sure if that's the cause. If there's nowhere the light is visible, it gets more awkward and requires some dismantling to check this possibility.
For confirming an LVDS cable fault, in the absence of test equipment to check the digital video data or the continuity of the tracks, you can see if there seems to be any correlation between movement and position of the laptop lid/screen and the problem showing, if so there might be a break in one of the flexible tracks in the loom. Another thing to try (and this also requires dis-assembly) is to clean the end contacts of the loom and re-seat the fittings into their sockets on the various boards. Sometimes tarnished contacts can cause these types of faults.
Edited by Platypus, 06 June 2011 - 10:21 PM.