Do LCD(TFT) monitor's hold time constraint....resembling 20000 Hrs or something...?

Answer:

yes LCD monitors enjoy a time constraint of about 30,000 hours after that you enjoy to replace the screen. but 30,000 hours is more than satisfactory.
backight has a life-life but you hold to call them manf for that info.. it adjectives depends on model..
its good to install lcd as it have more life as capably as it is compact
Yes. Their life depends on usage hours.
The monitor or display of a computer is the primary user interface. Monitor problems are some of the most adjectives computer problems since the voltages inside a monitor can be as high as 10 KV. Many of the problems can be fixed yourself by simply shifting the settings. Detailed instructions available at http://fixit.in/monitor.html