AOC LCD monitors have jittery images from time to time - News - Global IC Trade Starts Here Free supplier

Filter 18.432M

Received an AOC LCD monitor, the computer will sometimes shake the image when it is turned on, and sometimes it is normal.
Disassemble and see the power board capacitors have no big belly, the voltage is normal when the power is measured, and the voltage is the same when the image is shaken.

This way, only use an oscilloscope to quickly find the problem.
The 5V curve on the power board is stable.


The 5V curve to the driver board is also smooth


The 5V curve becomes thicker after the inductance (poor filtering)

Therefore, the 3.3V curve after voltage regulation is also a thick line.

Remove the two filter capacitors,

Replace with a good capacitor.
Measuring the 3.3V curve with an oscilloscope is smooth.


Finally, the image jittered again after several hours of testing.