First, you can unplug the computer & monitor from the EnerSave power bar and plug them into a surge protector or other AC power. If you do it without a surge protector, be sure to pick a time when there're no storms in your area! After testing, you should go back to your normal hookup. If the problem still persists, try booting to Safe Mode and see if that makes a difference. It could be that somehow your display resolution got set to something the hardware can't support. If neither of these things help, you've probably got a hardware video problem.
I hope this post isn't too vague. I did find plenty of posts on the web where others have the same problem of the monitor immediately going into power saver mode upon boot up. In my case, the monitor is Dell P190S, 18-20" about 2 years old, OS is Win7, Acer computer purchased December 2012. On start-up "Auto Detect (ANALOG INPUT) entering power save" mode is displayed. I couldn't get to Control Panel or bios of course because nothing displays on the screen. Using the buttons on the front of the monitor I got text display which indicated 'there is no signal coming from the computer' with a message to wake up computer by using any key. Of course I'd tried that with no change in the monitor display. I finally got a menu via those buttons on monitor and chose to restore factory defaults and was able to get a view of webpages and email etc.
So my question is: could this be a monitor issue or could it be that when the computer goes into power saver mode there is some conflict with the Globe EnerSave power bar I'm using? (the EnerSave bar basically shuts off all peripherals when shutting down the computer). Any thoughts or suggestions are very welcome!