Display refresh rate is set too low
When the refresh rate of the display is set below 75Hz, the screen will often appear jittery and flickering, and the refresh rate will be raised appropriately. For example, if it is set higher than 85Hz, the phenomenon of screen jitter will not appear again.
The power transformer is too close to the display and the chassis.
When the power transformer is working, it will cause large electromagnetic interference, which will cause screen jitter. Keeping the power transformer away from the chassis and display can solve the problem.
Inferior power or power supply equipment has aged
Many of the components used in computer power supply are poor in workmanship and materials. It is easy to cause the computer's circuit to be poor or the power supply capacity can't keep up. When the system is busy, the display will especially appear on the screen. When the computer's power supply starts to age, it is also likely to cause the same problem.
The speaker is placed too close to the display
The magnetic field effect of the speaker will interfere with the normal operation of the display, causing the display to produce magnetic interference such as screen jitter and crosstalk.
Some computer viruses can upset the screen display, such as: character inversion, screen jitter, graphics flip display. The screen jitter scripts that are everywhere on the Internet are enough to be as big as a cow.
Poor contact on the display card
After reinserting the display card, the fault can be eliminated.
WIN95/98 system write cache caused
For this reason, disabling all drive-behind caches in Control Panel - System - Performance - File System - Troubleshooting will allow the problem to be solved.
Power supply filter capacitor is damaged
Open the chassis, if you see the top of the power filter capacitor (the largest capacitor on the board), then the capacitor is broken, the screen jitter is caused by the power failure. After changing the capacitor, you can solve the problem.