I've been using a 20" CRT computer monitor in conjunction with edius as a monitor for studio shoots. Today I hooked up a 17" sony triniton crt, it's about 8 years old. The computer seemed to boot up okay but just before the desktop appeared I got a "out of scan range" message. What causes this? I think the monitor is okay as it works on other computers. The computer seems to be fine too, it's about 4 years old.

Means the resolution the computer's currently set to is too high for the monitor.

Boot it up with the 20" again and turn down the desktop res before shutting it down, or, boot it up with the 17" in safe mode. Then bump the res down.