AC40 Service Manual Page 27
Hold on to the knob and fasten the nut.
Check if the other knob has to be adjusted
Press the Mask on/off button, to activate it. Turn knob clockwise and anti-clockwise.
If the knob has to be adjusted, use same procedure as described.
Turn the knob clockwise and anti-clockwise, to see if the knob is correctly adjusted. If not, adjust it again!
Remember! The square should ONLY move after each “full click”/when ”it feels like the knob ’clicks’ ”.
Continue with this test, if the square moves before the knob completes one “full click”.