Well...I'm not too sure what your problem is but I would start by checking the following:
- Monitor cable connection to PC an to the back of the monitor
- Monitor power (is it plugged into a "working" outlet)
- Monitor settings (is the brightness turned down, etc)
- Can you use a different monitor on your computer?
- If so then it's the monitor.....time to repair/replace
- If not, then its the computer....check the video card
Hope this helps.
A bit of advise for you....try to be a little more descriptive in your questions.