Note: this is not a request for troubleshooting help.
For the past few years my 10ish year old “smart” TV will maybe once a week or so completely lose the ability to play sound in the Youtube app, and only in the Youtube app. Sound works just fine everywhere else. Bizarrely this is always triggered by an ad and never a video. Restarting the app doesn’t fix it, and neither does clearing the cache. Fortunately doing a full restart of the TV fixes it, it’s just irritating to have to restart because an ad somehow broke the sound.
What technological gremlins haunt you?
I had something like this one. It was the ram. If I powered off, shut off the PSU and unplugged, then reseated the ram and tried again it would come on. Upgraded the ram and the issue went away.
Also, if you encounter this with a Dell laptop, same thing (just make sure to disconnect the battery before touching the ram).