One of my macs has the same issue.
It's a Macbook Pro 15" Late 2006 MA610LL A1211
It's whether the screen cable's connector or the port on the logic board.
Whenever the black goes red I press down the keyboard, over the following buttons: [;'p
I don't feel like taking this laptop apart right now, but if the "pressure" workaround will keep working, I'll just open it up and apply couple of layers of electric black tape over the flex cable connection.