My 20 inch Dell Monitor keeps shutting down..

Change the default settings (both of the monitor and the BIOS). Chose the same mode (DVI or VGA).

1ST CHECK POWER CORD.

2ND CHECK CONNECTION ON BACK OF PC

3RD HAVE YOU INSTALLED, DELETED OR REMOVED ANYTHING FROM YOUR PC PRIOR TO THE MONITOR SHUT OFF ON YOU

I suspect your graphics card or processor is overheating and shutting itself off to prevent damage.

Cool the unit down with additional fans, introducing cool air and exhausting warm air is key to a reliable, stable computer system.

The reason for this sudden problem is most likely because a higher resolution on the new monitor is supported, therefore making the computer work much harder than before.

Take care!
damnor01

Time for a new monitor.

Dell monitors automatically go into power-save mode after a preset amount of time when the computer is inactive. The Dell monitor will go completely black, instead of showing a screensaver. This doesn't mean that your Dell computer has shut down. Instead, this allows your monitor to essentially turn off until it's needed again. You can change how long it is before the Dell monitor goes into power-save mode by changing your display settings.

1. Step 1 Press any key on your keyboard or move your mouse. Either will turn off power-save mode. Alternately, you can press the power button on your Dell computer tower or laptop.
   
2. Step 2 Press any key a second time if the monitor goes from power-save to stand-by mode. Stand-by mode allows the screensaver to appear.
   
3. Step 3 Enter your user name and password into the login prompt if your computer requires a login. Press "Enter" to begin using your Dell computer.
   
4. Step 4 Change the display settings on your Dell monitor to prevent your monitor from going into power-save mode prematurely. Right-click anywhere on your desktop and choose "Properties." Click the "Screensaver" tab and press "Power." Beside "Turn off Monitor," choose a time amount from the drop-down list and press "Apply."
   

Check the display power settings in Control Panel.

Sounds like the computer is shutting it down and the monitor is fine. Check for viruses then check your settings in device manager for the screen saver and power down (screen off) options.

I'm assuming you mean that you've tested the computer using another monitor and that the desktop proved to be working fine. If that's the case then the monitor needs to see a reputable repair person for repair.

This is probably a back light problem. Take a bright flashlight and while the monitor is on, point it at the LCD and try different angles, etc. If you can see an image, it is the back light, probably the back light voltage converter unit in the lcd. It could also be the back light bulbs.

If you don't see an image with the flash light, then it could be the main logic board.

ort11

its due to wahter problem its commen problem in a dell monitor u have to take ur monitor with a good electronic technision or if u have knowlged then u have change the id of u r ic in ur monitor & ur monitor will be redy to use