I have a (really old) PowerMac 7500, with a G3 upgrade, and the awful Apple 15" multiscan monitor. Anyway, of late the screen turns blue--I can still read it, but it has a strong blue cast. It lasts for 5 seconds to a couple of minutes, but then switches back. I'm guessing it's something in the video board. I've tested the connections, so it's not a loose cable. Any thoughts on the source of the problem? Man, I need some iMac or PowerMac updates to come soon . . .