Video RAM test-
"If a bad video RAM chip is found ... the system .. flashes out the bad chip's location on the halt light, over and over again separating the U#s with a one second pulse."
I've seen that in the manual however my board only flashes once every 3-4 seconds with no other flashes between. Almost as if the board is resetting every 3-4 seconds but I have no way of knowing for sure without seeing the image on screen.