NU monitor model #L921G

Here's some tricks I would try...
1. Verify the monitor's power cord is plugged firmly into the wall outlet and the back of the monitor.
2. Verify the monitor cable is firmly connected to the computer and the monitor.
3. Verify that you have turned the monitor power switch on.
4. If the power light on the monitor is not on, test the wall outlet (plug in a light or something you know works).
5. If the power light on the monitor is not on, try a different power cord.
6. If the power light is on and yellow or orange or flashing, but nothing displays, or the display is incorrect, borrow a monitor from a friend. If that works, your monitor probably needs replaced.
7. Also, you could try your monitor on a friend's computer. If it doesn't work, your monitor probably needs replaced. If it works properly on your friends computer, the problem may be with your computers video output port, motherboard video chip (or video card, if you have one), or drivers.
Good luck.

Here's some tricks I would try...
1. Verify the monitor's power cord is plugged firmly into the wall outlet and the back of the monitor.
2. Verify the monitor cable is firmly connected to the computer and the monitor.
3. Verify that you have turned the monitor power switch on.
4. If the power light on the monitor is not on, test the wall outlet (plug in a light or something you know works).
5. If the power light on the monitor is not on, try a different power cord.
6. If the power light is on and yellow or orange or flashing, but nothing displays, or the display is incorrect, borrow a monitor from a friend. If that works, your monitor probably needs replaced.
7. Also, you could try your display on a friend's computer. If it doesn't work, your monitor probably needs replaced. If it works properly on your friends computer, the problem may be with your computers video output port, motherboard video chip (or video card, if you have one), or drivers.

Good luck.

1. Verify the monitor's power cord is plugged firmly into the wall outlet and the back of the monitor.
2. Verify the monitor cable is firmly connected to the computer and the monitor.
3. Verify that you have turned the monitor power switch on.
4. If the power light on the monitor is not on, test the wall outlet (plug in a light or something you know works).
5. If the power light on the monitor is not on, try a different power cord.
6. If the power light is on and yellow or flashing, but nothing displays, or the display is incorrect, borrow a monitor from a friend. If that works, your monitor probably needs replaced.
7. Also, you could try your display on a friend's computer. If it doesn't work, your monitor probably needs replaced. If it works properly on your friends computer, the problem may be with your computers video output port, motherboard video chip (or video card, if you have one), or drivers.

this could be a graphics card problem either it has not been installed properly or it might be faulty or the drivers for it or a dirty socket you im not sure about a Mac?
Click start control panel administrive tools computer management device manager scroll to display adapters + to expand you might see a yellow question mark ? or exclamation mark ! red x right click select reinstall drivers if your computer came with a motherboard disc the drivers could be on it or you could download cnetdownload.com on the home page you should see the download software finder under that there will be a list platform, category sub category price from the category drop down list select drivers then from the price drop down list select free or which ever applies to your need
you could get this on Ebay if you dont have an account you will need to create one
Add Email adress
Add Bank Acc
Add Credit Card
also add your postal adress
also add a paypal account
when you get to the paypal login page at the bottom you will see new to paypal sign up tab
paypal to create an account
paypal registration password ,bank card /credit card,phone numbers home/mobile ,email adress and a postal adress
be very specific when you type in the search
always ask questions? before you make a purchase and keep the email/s for security reasons if the item arrives and its not as described
you will even see the pictures of your item so you cant make a mistake and get them home delivered

hope this helps

Below you will find my recommendations for troubleshooting this issue:

1. Reseat the power cord and verify a good power source.

To reseat the power cord, follow the steps below:

1.1 Power down the system.
1.2 Unplug the power cord.
1.3 Wait approximately one minute.
1.4 Reseat the power cord.
1.5 Verify that the power cord is plugged directly into a known good power outlet.

2. Verify that the monitor is receiving power from a known good outlet and bypass any power strips.

To test the power outlet, perform the following steps:

2.1 Unplug the monitor power cable from the power outlet.
2.2 Plug in a different device, and verify that the device is operational.
2.3 If there is no power try another outlet. Remove any power strips and try plugging directly into the main power outlet.

3. Verify the monitor is powered on and the power button is engaged.

Ensure that the monitor is powered on and that the power button is fully engaged. To do so, check the power LED on the front of the monitor; it should be lit.

NOTE: There are two types of power switches:
A mechanical switch characterized by a long travel. You have to push it further and you will hear an audible click.
An electrical switch that has a short travel and almost no click.

A lit monitor LED can be any of the following:

* Green
* Blinking green
* Yellow
* Blinking yellow
* A combination, such as alternating green and yellow

Any of these states indicate the monitor is receiving power and that you should proceed.

4. Swap power cables.

To try a known good power cable on the monitor, follow the instructions below:

4.1 Turn off a working monitor.
4.2 Unplug the cable from the back of the working monitor, and unplug the cable from the wall.
4.3 Unplug the cable from the monitor in question.
4.4 Plug in the cable that came from the working monitor.

5. Run the monitor self test.

To run the monitor self test, perform the following steps:

5.1 Power off both the computer and the monitor.
5.2 Unplug the video cable from the computer or video card.
5.3 Reseat the power cord to the monitor, ensuring it is plugged into a known-good outlet.
5.4 Power on the monitor.

NOTE: The monitor self test will move around on some monitor models. If the monitor self test moves, allow it to move to the affected areas of the monitor to check for the problem described.

If the Self test failed, it's possible that the monitor is faulty. Contact dell to check if it's still under warranty so they can replace it.

Sounds as though the power cord reset switch might be bad and need to be replaced. If not, then there is a short somewhere in the system. Do an ohms test on the switch to determine if it is bad.

unplug it then plug it back in

Check power board.

you can go to any monitor repair shop & get it.

just tell model no. or take the sample which is defective.

good luck.