Issue: I was not getting any sound when I connected the HDMI cable from my laptop (LG Gram 15) to an external monitor (Samsung Syncmaster PX2370).

Additional info: The monitor is not connected to any external speakers.

Fix: Control panel → View by: Small icons → Sound → Playback → Select a playback device below to modify its settings: → select “Speakers; Conexant HD Audio” → Set Default → OK.

Before I changed it to the above setting, it was set to “SyncMaster; Intel(R) Display Audio” which was not working.