[sleight]

How old are the CRTs? I have a recurring problem here at work where fairly old monitors will blink off into the orange no signal mode, then click back. Every time this has happens it continues to escalate until finally they just end up in sleep mode forever (their souls residing wherever dead pieces of monkey%&@!# go).

Rereading your original post, do both of them blink on and off at the same time? Wouldn't that point towards the video card?