If your ARTSEA projector has no sound, you can check the following solutions for troubleshooting.
1. Check whether the sound is muted. Adjust the volume with remote control of the ARTSEA projector.
2. Check whether the external cable is well connected when you connect the ARTSEA projector to external devices.
3. Check the Audio Setting on your Amazon Fire TV and try turning off Dolby Digital Plus, and the sound will be normal.
4. Use the other remote control to adjust the volume when you connect the projector to a TV Box or other devices.