To configure the playback channels, go to the console’s menu “Routing” / “Home”.
For example, to playback from USB harddisk to the mixing console’s local analog inputs, select “input 1-8” to “card 1-8”, and so on.
In your case please check that static noise still exist if you are changing the routing. Please try to set 1-8 channels to all places then check the noise again. If you have no noise you can try to set up the 17-24 to multiple places then check the noise again.
I looking forward for your feedback