If you're getting audio output on external headphones, your sound card is working... it could be that the headphone jack isn't reconnecting the speaker when it's unplugged.
Older jacks had a little switch that was pushed aside (just a metal strip) that disconnected the internal speaker. Newer ones do it digitally. If you have an older jack, you might try spraying a Q-Tip with contact cleaner and swabbing inside the jack.
If it's a newer one that connects / disconnects the speakers digitally, I'm not sure how to proceed, but there's a command that'll do it. You'll have to peruse the developer's manuals for your sound card or computer.
It could also be that your internal speaker has died (either the coil is shorted or open-circuit, or the driver magnet has rusted in its tube and cannot move, or there's so much dust at the back of the speaker that it's impeded in movement)... if you can, take the machine apart, disconnect the speaker leads if you can (there should be a tiny plug you can unplug, or the speaker will have spade connectors), get a 1.5 V AA battery and some test leads, and repeatedly connect/disconnect the battery to the speaker terminals... if you hear it clicking as you do so, the speaker's still good.
Gday @Bennolo ,
Yes with a clean install it may take a few updates/ adjustments.
Without headset plugged in,
Try running the software & updater, click " settings" at the bottom & select the Additional Drivers 'Tab',
After update, Reboot pc.
Then try installing ' pulseaudio volume control ' from the 'software store' app.
Open pulse,
In the output 'Tab" , make your internal speakers " set as fallback'.
In the config 'Tab' make the profile set to " Analogue stereo Duplex".
Reboot & try,
Other thing's,
New app's installed,
Open ' Startup applications', & disable thing's like " Zoom" or Messenger app's etc.
Let us know how it goes.
Ok, we'll check the hdajackretask route. I assume you've already got alsa-tools-gui installed?
sudo apt install alsa-tools-gui
hdajackretask
Ensure your sound card is selected, then toggle the speaker to 'Unconnected', then 'Show unconnected pins' and select one of those pins as the speaker output (override), then click 'Apply' and try it, ensuring your speaker volume is up. If that's not the right pin, try again with another.
Might be a good idea to have a movie or music playing the whole while you're doing the above... as soon as you get it right, you'll hear your speakers.
If all else fails, toggle your headphones to 'Unconnected', then connect the speakers to that now-unconnected pin.
