I got wide tracked...replacements came in...kind of an ordeal to replace-literally have to almost completely disassemble the entire unit, which is actually why I didn't snap the pic...I went to it and realized how much disassembly work there was...brain onto other things.
New ones are bright and shiny. So much so that after the first extender fired up, I decided it would be best to use the second display for the main unit, which was hella dim by comparison.
I still think though that when I get time, I'm gonna play with the "not working" ones...see if I can isolate the backlight. When I first replaced the main unit, the new LCD acted just like the dead ones--turned out to be a slightly, and I mean slightly not fully seated ribbon cable. Makes me wonder if reseating it on the extender that still has the dead backlight would fix it...that won't take long to test.
Mackie Support ended up being pretty helpful on subsequent calls. And, they're back ordered on the part AGAIN...makes me want to get a few extra...