GE vivid E9 ultrasonic trouble shooting(4)

Fault phenomenon

There are no obvious interference or problem images when examining the patient, but occasionally the image will feel like snowflakes drifting, and there will be small areas of snowflake interference when using the keyboard.

Fault analysis&Troubleshooting

First check the keyboard USB input voltage, measure the voltage is normal, there is no obvious voltage change, and the shell is not charged. Test DCDC output voltage is normal. When I checked again, I found that the keyboard popped up not smoothly and smoothly. Raised the console, and found a problem: the ground wire under the keyboard got stuck in the slideway, and it was found that the exposed metal wire of the ground wire touched a metal object, there would be interference. This ground is a protective ground. Grounding is to protect the earth leakage of electrical components when the skin is damaged. It has a certain protective effect.
When the cable was reconnected to the grounding slot, the failure did not occur again.