The Prowise EntryLine UHD has lost all sound, what can I do about this?

Check the following settings in the Prowise Central menu:
Is the volume set at a value higher than '0'?
Is there a physical connection between the Prowise EntryLine UHD and external headphones? 
- If so, the audio is muted since it is playing through the earphones.
- In the settings/audio/output menu, select internal (only audio output via the touchscreen) or both (audio output through earphones and the touchscreen).
- Or remove the earphones (2) so the sound is no longer muted.

Check whether the output is set to External.
- If so, the speakers are muted because the sound is set to play though an external speaker.
- Select 'internal' or 'both' to activate the speakers on the Prowise EntryLine UHD. 

Check whether the Mute feature is activated.
- If so, the speakers will be muted.
- Disable the mute feature to let the sound play through the speakers of the Prowise EntryLine UHD.

In case the internal PC module is used as source, check:
- The Windows volume settings
- Device that is playing (in the Window audio settings)
     PC monitor 2 (Intel Display Audio)
- Audio drivers.
     Update the Audio drivers for the Prowise Intel Display Audio device in the Windows device manager.

In case an external PC is used as source, check:
- The external cabling of the external PC to the Prowise EntryLine UHD.
- Whether the Windows volume settings are correct.