Monitor Not Showing A Picture. Light flashes Yellow and Green.

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, borrow a monitor from a friend. If that works, your monitor needs replaced.

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, borrow a monitor from a friend. If that works, your monitor probably needs replaced.

Try monitor on a different computer, if you get the same results, try swapping out the VGA 15 pin cable.

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.

is there power to the monitor? is the monitor in standby(yellow light on monitor)? is the monitor on (green light on monitor)? how is the monitor connected to the computer, VGA (square fat cable, the end may be blue) or HDMI cable? When you turn on the computer is the power light on and HDD light flashing / showing activity? this would indicate that the computer is booting up. If you have power light and activity on the computer, I would unplug the data cable to the monitor. If the monitor is plugged in, i would press the power button to try and turn on the monitor / take it out of standby. If the monitor is ok you should see a message like "no signal" or "no input". This would tell you that the monitor is fine, but you may have a problem with the video card or video port on the motherboard. If you have no activity light on the on the computer, you may have a problem with the OS not booting up. You really didn't provide much detail on what has been done, but this is how I troubleshoot out in the field when working on something like this.

check the vga cable which get loose connection then the signal from pc not recognized.

Could be the Graphics card is out, or the VGA cord is damaged and isnt giving video but is giving some sort of signal to engage the monitor.

First please check whether the Monitor powering ON or not
the see the colour of light of the monitor i.e, its green or orange or not glowing next see that all the lights showing but constantly flickering or else just see u r VGA or DVI Cable which is connected properly to the CPU if it is ok then remove the cable connect only the monitor to different machine in case still not comming then finally it is a monitor problem or else just check all the connections inside the CPU

In case its monitor problem either it will not power ON or else all the lights will blink constantly that means the refresh rate or the Resolution of the monitor has been changed in case if it is done just connect a different monitor boot in the safe mode by pressing F8 button after entering there change the resolution which will be in the display properties apply and reboot the machine or else turn off u r PC and connect u r Old Monitor and Boot the Machine

Did monitor work's on another pc?

If YESS so u need to change ur VGA

That usually means that the connection between the PC and the monitor has been interupted- check that the cable (probably has blue ends) between the two is firmly connected, and power it back up. If that doesn't work, you have one of three problems; a broken VGA cable, a broken monitor, or a broken video card. Finding out which- you'll actually need someone tech-savvy there to help you figure that out. Try plugging the monitor into a different computer. If that fails, use a different VGA cable (cables are pretty cheap at monoprice.com), and if that fails, it's your video card.