computer screen has a mind of its own

[greatgranny123_-]

my computer screen keeps jumping up and down, very annoying. Also keyboard only types sensible letters when its in front of the screen and not the tray part of the desk. Have I got gremlins in the works?

[johnymsmith]

Because may be some loose connection it happen, check both ends of the VGA cables.
Also In some cases, a jumpy screen is caused by a malfunctioning mouse. Try a different mouse on your computer to see if the screen continues to jump. If not, then old mouse was creating the problem.

Sometimes A Monitor failure can produce odd screen behavior, including flickering, jumping and color changes. Older, large CRT monitors contain components inside that degrade over time, and are susceptible to magnetic interference, both of which can produce a jumpy screen image. Connect your jumpy monitor to another computer and see if the problem persists. If it does, it's a good indication that the monitor itself is at fault and needs replaced.

OR A virus can alter the way your monitor communicates with the mouse, graphics card or motherboard, which can in turn cause screen issues such as jumping. Run a virus scan to find and remove any hidden invaders that may be causing your screen issues.