I tried inputting a white signal and cannot see the lightening.
Also, I tried red, green and blue signals and they all seem OK.
After extensive scrutiny -
You can't see it on v. dark or v. light images, only medium images (blue skies for instance).
The topmost and bottommost 2-3 rows of pixels are lighter than they should be and the next 2-3 rows pixels inside are slightly darker.
This happens on every screen mode - full / widescreen etc.
I phoned Sanyo technical helpline - the chap told me it was dust on the panels and suggested I clean them with the puffer. Didn't have a lot of confidence in that advice but did it anyway - no change.
Amusingly, I was getting obsessed with the mild
VB until I saw the light bands at the top and bottom of the picture. Now I don't notice the
VB.
Perhaps, I've got a compulsive/obsessive personality