1. Low battery power: If the water pump is powered by battery, it may be that the battery power is low, resulting in a black screen and constant noise. Try replacing the battery with a new one or connecting the pump to the power adapter.
2. Equipment failure: Black screen and continuous noise may also be caused by equipment failure. In this case, it is recommended to contact professional maintenance personnel of medical equipment or Medtronic's customer service center for further technical support and maintenance services.
3. Operation error: Black screen and noise may be caused by wrong settings, unexpected key operation or wrong parameter settings.