dbx AFS224 Quickstart Guide - Manual (Page 7)

12. Pull the master faders on the mixer all the way down (no signal).
13. Check the Mode buttons. If they are not lit green, press the buttons until they are
lit green. None of the filter LEDs should be lit at this point. If they are, press and
hold the BYPASS buttons until the filter LEDs flash, then release. All filters
should now be cleared.