LG Flatron 21" Computer Monitor has no signal please help as swith on but no screen from computer?

SOURCE: LG Flatron 775FT monitor distortion

Doesn't look very good :( You can try returning to the "factory settings" in your monitor's menu. Maybe try the monitor in another computer to check whether your graphics card is faulty. But all in all it looks like a fault from the monitor :( Good Luck!

SOURCE: Lg 1919s flatron monitor slowly gets dark

This problem is showing when the main PCB of the monitor failed. Contact the LG service provider in your area. They will change the full package assembly or PCB. check this link to get the service center info
http://www.lgservice.com/

SOURCE: LG Flatron w1952TQ (black)computer monitor

this page gives you some charts to use to calibrate your monitor by eye. I have the same monitor and have not found out how to adjust the luminance value yet.

http://www.drycreekphoto.com/Learn/Calibration/monitor_sensitivity.html

SOURCE: monitor LG FLATRON E700SH

Sir,
I hve read all above statement which shown as above. but in my case monitor take time to ON and display the screen, its take at least 45 minutes to start up and display the window screen. So please to send me solution about my Query.
Thank's

SOURCE: LG Flatron Monitor-adjust height and color

https://support.dell.com/support/edocs/monitors/1908FP/en/ug/stand.htm#Using%20the%20Tilt,%20Swivel,%20and%20Vertical%20Extension
4:29:29 If locked in the down position, 1. Push the monitor down, 2. Press the Lock down / release button on the bottom rear of stand to unlock the monitor. 3. Lift the monitor up and extend the stand to the desired height.