External Speaker Fails to Mute Internal Speaker

I am running Windows 10 Professional with current up-to-date updates on my Dell Inspiron Laptop.

Several days ago I noticed that plugging in current headset no longer muted the internal speaker. I know that it is not the headset as it works perfectly on another computer.
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Doing a web search has not resulted in finding the problem, let alone a solution. Further my anti-virus is up-to-date, as are the microphone and speaker drivers.

Pointers in the direction of a solution will be much appreciated.

Thanks in advance.

What audio codec does your laptop use?

It will be listed in device manager. The VEN DEV combo will be enough information.

You'll find it in the device properties details tab, specifically, the "Hardware IDs" section.

It will resemble this:

Code:

HDAUDIO\FUNC_01&VEN_10EC&DEV_0288&SUBSYS_10EC0191&REV_1000

Usually the audio codec chip itself will detect an external speaker is plugged in. Have you checked your audio device's configuration software? It should have a shortcut in the classic control panel.

Problem solved! The wrong speaker was set as default in the Playback section of Sound in the Control Panel. One mouse click and the problem was no longer.