Press the button on the projector or the remote control to turn up the volume.
Make sure A/V Mute is not enabled. (The A/V Mute button on the remote control may have been pressed.)
Make sure the A/V mute slide (lens cover) is open.
If you’re using a DVD player or VCR or other video source, make sure its volume is not turned all the way down or muted. Also, make sure the cables are connected correctly. See Playing Sound Through the Projector.
Make sure you are using a “no resistance” audio cable.
Make sure the audio cable is connected securely at both ends. For computer audio, connect the cable to your computer’s headphone jack or audio out jack.
If your presentation includes computer audio, make sure the volume control on your computer is not turned all the way down or muted. In Windows, you may be able to use the volume control in your Windows system tray (lower right corner of the screen). On a Mac, you may be able to adjust the volume from your menu bar (top right corner of the screen) or via the volume control function keys.
If you are using a microphone connected to the projector’s Mic port, make sure the cable is connected correctly and the Mic Input Volume option on the Settings menu is adjusted correctly. See Customizing Projector Features.