What happens when you try to activate the TV's volume control or the TV's menu, do they display on the screen?
Do you see any blinking lights on any of the boards?
I'll take a look at that, but roughly speaking...you're descibing a Zsus issue.
You mentioned you replaced THAT BOARD?
Do you still have the Original Board? If so, I'd definitely compare the Sticker on that board to the original and verify it's the same board. Then I'd look at where that board came from. I'd feel more comfortable if it came from the manufacturer, one of their Distribution Warehouses instead of EBay or a scrap TV set.
But we should compare the original board with the replacement.
Oh wait....you stated YOURS looked like that...this is someone else's TV where they replaced all the boards....Correct?
Ok, it's still the same issue, because Zsus boards, when they fail, you get a picture, but it's actually those speckles/blobs you see, and they have a tendency to change/move due to the actual video signal.