I'd need to see it myself before I'd venture a guess because your description isn't giving me enough to go off of, but since you have a technician coming out, this may be the best option.
So I have a Samsung PN51D550C1F. Everything looks great til I watch 3D. When their is a dark or solid black screen (like switching to 3D) I get great and red pixels in the center and right part of the screen. While watching 3D with dark screens I get the same thing. Any idea of what this may be? Is it fixable? I have a 2 yr warranty through Bestbuy, the tv is one year and a tech will be out tomorrow]