Tha display screen is dark, shows very faintly.

If you try already adjust the brightness and contract and still not working. Try this, open the cover of your monitor but make it sure that the power is unplug. In the back of monitor board look for the plyback. It is usually black color with some wire connected here from the monitor yoke and picture tube. At the body of the plyback there is two adjustment holes . the upper hole is for the screen control and the lower is for the focus. You can adjust the screen monitor brightness by use of sharp thing or flat screw driver. Open the computer and monitor then slowly rotate the screen adjustment look for the desire brightness. But make it sure that you don't touch some parts of monitor to avoid electric shock. If your screen display blurred try to adjust also the focus do it with care.

Can you be more specific ?
The first step is to isolate the system at fault:
1) Monitor hardware ?
Test it on another PC or
Try a different monitor on the same PC
Check monitor adjustments.
Check the video cable, try another one.

2) What kind of a monitor is it?
CRT (like and old TV) or an LCD flat screen

3) Video card problem, possible but not as likely

4) Video driver or operating software settings issue
wrong video mode, video settings the monitor can't handle,
incorrect device driver

lots of possibilities here.
MJS