Was told that it may be the A board that went bad or it could also be the D board. Can anyone help and also give me some pointers on how to change these boards out and is it difficult?

Probably not the A board (since you have sound), but it could be. It could also be your SC, SS, or D boards. Without testing it, it is impossible for me to say for certain which board it is, especially since it isn't shutting down.

Your best bet is to have a repair technician look at it. If you aren't careful when working on plasma TVs, you can actually damage different boards.

What do the SC and Ss board do?

Without getting too technical, they drive the panel. So when they fail, you can have picture problems or no picture at all.

They are generically referred to as the x-sustain and y-sustain boards or x-main and y-main.

Thanks for your help fadedmaster. It was actually the D board that went bad. Was able to get my part from shop jimmy for $42 and labor was $120 not bad. Considering if I had let the repair shop buy the part it would have been $150 plus the labor. And don't go to Panasonic for help all they do is give you a headache. I still love my TV but I will never buy panasonic again.