Check the following settings.

■ When [INSERT] is selected

1. Select a source of input sound using the [INSERT SOURCE] selector switch.

2. Make sure the [INSERT] button in the MULTI I/O section is blinking.

3. Check the [SEND CH] selector switch to see if the channel you want to apply the effect to is selected.

4. Check if the [SEND LEVEL] knob is in the proper position.

■ When [RETURN] is selected

1. Set the input selector switch for each channel to [RETURN] or [USB].

2. Check the [CH SELECT] switches to see if the channel you want to apply the effect to is selected. The channel to which you want to add effects and the channel selected with the input selector switch in 1. should be different channels.

3. Check if the [SEND LEVEL] knob is in the proper position.

4. Check that the [TRIM] knob for the channel selected in 1. is in the proper position.