After opening the microphone, there is noise all the time. And the other conference sites can’t hear clearly.
1. There is still noise after the tone board local loopback in operation bench.
2. Open the shelf and replace the AUD board. The noise still exists.
3. The noise still exists when we pull out the assisted microphone.
4. Insert the assisted microphone and pull out the main microphone, the noise disappears.
The noise may be caused by the transit card with poor quality or the jack is broken when user plugs the microphone.