If colors are impure:
Check signal cable connector pins. If pins are bent or missing, consult your
If faint black vertical lines are visible on the screen:
The aperture grille may be mis-aligned. Shock or vibration during transport
may, in some cases, cause the aperture grille to fall out of alignment. The
problem will appear as one or more faint black lines across the screen. If
this problem occurs, it may be solved by either degaussing the screen or
by lightly tapping (do not hit) the side of the monitor.
However, if neither of the above methods work, attempt the following:
Display a black field over the unaffected areas and a bright white field over
the area where the black line(s) appear. Do so by opening a bright-white
window on top of a black desktop or wallpaper background. Position the
window so that it just cover the area of assignment.
Set brightness and contrast to maximum values. Keep the display on until
the problem is solved. Try tapping (again, do not hit) the side of the display
lightly to expedite realignment. The white field will heat up the mis-aligned
area of the grille, returning it to proper alignment.
If there are two horizontal hairlines visible on the screen:
It is not a defect. These are dampening wires which are used to support the
CRT's aperture. They are visible as thin dark lines across the screen.
2 Troubleshooting and