I read your post a while ago and had to ponder how to reply. Here's my thought. You seem to want a new perfect machine but are dealing with used and repaired units.
I think that's the issue. The reason all those are in those channels is simple. They are less than perfect but you are getting them for less.
Maybe it's time to get a new machine with warranty and more?
Bob
Hi everyone. I recently purchased an off-lease Dell D610 laptop only to find it had a white depression mark in the middle of the screen. I have since had the screen replaced by the seller; however, I'm not certain the new screen is up to snuff either.
Apart from a few stuck pixels (which I can live with) the laptop is like new. Unfortunately, my main complaint is that the screen also has a slightly dim border approx 2" in width all the way around.
All images are still visible and bright. The border is simply "less bright" when compared to the rest of the screen -- almost like the white reflective backing has started to bend and lose contact with the rest of the LCD display. This "border" does not have a straight edge; instead, it seems to meander a bit, but the edge is definitely well defined. It is also more visible when displaying solid dark colours.
Anyone have any experience with this. Is it fixable? I'm not really interested in going through the trouble of having the screen replaced with another sub-par unit and will, instead, try to fix it myself or simply replace it with a brand new screen.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic