As I indicated earlier, I got all three boards for a ridiculous price so I purchased all three instead of just the main board. I initially replaced both the main and the power supply boards thinking if there was something slightly out of whack with the original power supply board that I didn't catch, it might take the main board out again. Upon plugging it in I immediately noticed the backlights stayed off until the unit powered on and whoppe, a screen full of snow appeared (it was on TV input) and message boxes. Woohoo! I put a DISH signal through it and got picture and sound.
I was running an HD signal through it yet I wasn't getting full screen. In the menu it was set to 16:9 so I was a bit confused. Then I noticed a bit of graininess, kind of like sparkling in certain parts of the screen. T-Con board.
So I replaced that and tada!! Everything is now OK. I upgraded the firmware to the latest and it's now running for a few hours to see if it remains stable. So that lightning strike definitely took out two of the three boards and most likely damaged the power supply board as well. Geezzz.