Solid green light and no activity on the screen.

I am having this same issue with a Bravia (KDL-40W5100) 40" tv. I do receive an error code of 10 red blinks with the original main board installed. I purchased a replacement, and once installed I don't get any blinks--it's like it isn't powering the main board to engage the software. Solid green light and no activity on the screen.

I have also replaced the T-con board with no change. I'm leaning towards an issue with the power, but having three boards, I'm not sure which one to start with: D1, D2, or the G6 board.

Any help with next steps would be greatly appreciated.