dell monitor stuck in power safe mode windows xp

99% it's an issue with the computer not starting. Exactly what happens when you hit the power button on the computer? Lights and fans spin up OK? If you are using an add-on video card, switch to the motherboard video connection if there is one, try again. Open the case and check the motherboard for issues with the capacitors, they should all be flat and shiny, if any are puffed up or leaking stuff, you need a new motherboard. If that looks good, unplug the power supply from the wall, take out the CMOS battery on the motherboard for about 15 seconds. Hold in the power button for about 15 seconds. Plug in the power again and try it. If that does not work and you have a few RAM sticks installed, try running with one stick at a time in the main RAM slot.

If none of that worked, you could have a dead power supply or a dead motherboard as the two most likely things, maybe the video card if you have an add-on one.