The main parameter when choosing a monitor is the screen's scan frequency. The higher the maximum value of this parameter is, consequently, better. For monitors with cathode-ray tube the values in the 60-70 Hz are considered extremely low, in this case, the vision may drop quickly. If you equate the same frequency, but modern monitors on liquid crystals, these values are quite acceptable.
Cause monitor flicker can be any factor which it is advisable to get rid of. In rare cases, this breakage of the device monitor. Let the manufacturers promise that their product will serve you for the entire warranty period, in reality not always so. The fact that in any industry there are a percentage of the production marriage. Maybe your case was exactly that.
Anyway, marriage or not, to a specialist service centre. The next cause monitor flicker can be low value the updates on-screen images. As mentioned above, the number of Hertz will affect the perception of the image: a low value of the screen's scan makes eyes tired quickly.
To change the value of the sweep must go to settings of your video card and monitor. If you are running Windows XP, just right click on a blank spot on the desktop, in the shortcut menu, select "Properties".
You will see a window where you navigate to the "Settings" tab, then click the "Advanced"button.
In the opened window go to tab "Monitor". Change the value of the row refresh Frequency of screen", it is advisable to put the maximum value, but not less than 60 Hz. Then double-click the "OK"button.
If you are running Windows 7, just right click on a blank spot on the desktop, in the shortcut menu, select "screen Resolution".
In the opened window click on "advanced settings" and set the value in the row "screen refresh rate".