Internal speaker is not showing in system preferences

I just found a discussion from 14 years ago which suggested inserting and wiggling an audio cable in and out of the jack a couple of times and that just worked for me! Given it was for an old G5 and I use an iMac it still worked.

"On most G5s, if anything is plugged into either the front headphone or the rear audio-out socket, the puny internal speaker is disabled - so you could try wiggling the jack in the socket to see if the cut-out switch is flaky." - Original Info I found from 14 years ago

Try resetting the SMC

How to reset the SMC of your Mac - Apple Support

Is there anything plugged into the Headphone port, it's generally that or a problem with the jack itself.

I had same problem. The Internal speakers were NOT ON THE LIST of sound output devices in the Sound dialog.

No devices connected to any ports.

I (plugged in headphones, unplugged headphones) x 10.

I shutdown, waited a minute, restarted.

I then upgraded to the latest bug fix operating system approved by my business (10.15.6).

I shutdown, waited a minute, restarted.

I shutdown, waited a minute, restarted, a second time.

Finally got the speakers back

Did the headphones work?

Catalina has been a pain for many & I doubt it'll be fixed when 10.16 is out & about.

Do you have a Time Machine backup to Restore to/from?

https://support.apple.com/guide/mac-help/revert-to-a-previous-macos-version-mh15216/mac

I am having the same issue with Internal Speakers not being an available option in Sound preferences. Only Digital Out and my Apple TV are shown as options. I am running on a mid-2011 iMac running High Sierra (10.13.6). I tried resetting the SMC but that had no effect. Any help would be appreciated.

I did all kinds of things like you but more. Then I went to a certified Apple service company. They thought it was a damaged motherboard - and its no longer supported by Apple. Parts are hard to come by and it will cost too much. So, for the next couple weeks, I continued using it while I figured out what was the best plan. After some time, its now working again. Don't know why or if it will last.

How's it going?

Not show internal speaker in sound systeams and not sound at my macbook pro. thank you

Did you ever get this resolved? I have the same issue, have tried the resets suggested here and still have the problem

Having the same issue here. Nothing is plugged into any ports, my software is up to date, I have tried restarting and still nothing is working.

Yes.

Some kind of miracle. But unpleasant one.