Computer monitor comes on for 1 seconds, flashes "analog power save mode" and then goes black.
Most monitors will say "Power save mode" when they can tell through residual voltage that the signal lead is plugged into a machine, but there's no picture being transmitted. The four states of a monitor are:
* Off entirely.
* Switched on, plugged into a computer but no video signal being received - usually displays "analog power save mode" or "digital power save mode" for a few seconds, then blanks. Comes back to life the moment a video signal is received. This state is the default in full power saving mode.
* Switched on, not plugged into a computer. Some monitors don't display anything, some go into power saving mode, some fly "CHECK SIGNAL CABLE" or a similar message around the screen. Picture is restored when the signal cable is plugged back into the computer
* On fully, receiving an image, and displaying.
Hope this helps.