Video card and monitor tips
How to test a monitor...
First you should get hold of a diagnostic utility like AMIDIAGS, QAPlus, Display Mate Utilities, etc. Display Mate Utilities is very comprehensive, though a bit technical, and is recommended.
General points to check for -
Before starting your testing set the brightness of your monitor by first turning your brightness knob (usually marked by a "sun" symbol) till the screen background turns white. Then reduce the brightness till the background just becomes black again. This should occur when the brightness knob is near about the center of its total turn. If this is too much away from the center in either direction then the monitor needs adjustment. Some monitors have knobs which give a tactile feedback when the knob is at dead center.
- Display a fullscreen colour closeup image of a well known movie or TV personality. See if the colours are properly shown. Look at the flesh tone to base your judgement on. In case of monochrome monitor the shading should be proper.
Check if the aspect ratio or the length to breadth proportions of the image is okay, for example, the shape and size of the nose should be in proportion to the whole face and should be as you remember from the movie or TV screen. - Geometric figures
Geometric figures like circle and squares should appear as circles and squares at all the resolutions supported by the monitor. Vertical and horizontal lines should not tilt or curve or be distorted in any way. Any deviation should be unacceptable. - Check if the screen flickers with uniform colour backgrounds or reverse video.
- Sharpness of high intensity images should be more or less same as low intesity images. One good way is to see if the inner black portion of the top of the letter "i;e" is easily distinguishable, in text mode.
- Check the monitor performance at the highest resolution specified by the manufacturer. Most of the monitors don't work properly at their highest resolution!
- Check if the overall brightness of the display changes/distorts the image. This will be quite apparent when a large and bright image is displayed.
- Check if on changing video modes does the display bounce or shake. If it bounces then how long does it take to stabilze. Also check whether the monitor makes a "squealing" sound. The sound and excessive bouncing (i.e. the display takes a long time to settle down) is not a good sign.
- If the monitor has a power saving feature then check if it makes a sound (like a sharp click or rip) when going into stand-by mode. The sound is not desirable.
Finally don't go by the monitor specification chart or the vendor's verbal assurance - check for yourself. Some of the noises which a monitor makes may indicate a big problem later on.