I think there's a typo there as most of those jumbo-tron screens are maintained by the company that made them.
As to the brand I worry there's a typo there as well. Please correct those so there's no guessing how huge or what make it is.
If a board is all in one, then it's just one board that you find on shopjimmy.com, ebay or where ever you find such things.
I need to replace powerboard on a 50' westingouthouse flatscreen. It appears to be combined with the video board as well. Static and flicker w/without video input. (Flicker on menu screen also) So cables and source are not the issue. Down and dirty swap advice would be welcome.