"Michale Norton, first off start with what Vizio suggest on here:
Built-In Speakers
If you cannot hear any sound from the speakers built into your VIZIO TV, check the following:
The volume level is set above zero.
The TV is not muted.
Under Audio or Audio Settings on the on-screen menu, TV Speakers is set to On.
All of the cables physically connected to the TV and the input devices are secure.
Switch to a different input device and verify there is sound from the TV speakers (for example, a DVD player or a gaming console). Turn the other device on and then use the INPUT button on the remote to switch to that device. Then attempt to play a DVD or game to determine if the TV speakers produce sound. If you do not have another device, and your TV is a VIA Smart TV you can test with any video application.
If you have a Cable or Satellite box, confirm that the audio is turned up and not muted within that box.
External Speakers, Sound Bar, Surround Sound System, or Other External Audio System
If you have an external audio system connected to your VIZIO TV and you do not hear any sound, check the following:
The volume control of the external audio system is set above zero.
The external audio system is not muted.
All of the cables physically connected to the TV and the audio device are secure.
Switch to a different input device and see if there is sound (for example, a DVD player or a gaming console). Turn on the other device and then use the INPUT button on the remote to change to that device. (Cable, Cable Box, DVD player, etc). Then attempt to play a DVD or game to determine if the speakers produce sound. If you do not have another device, and your TV is a VIA Smart TV you can test with any video application.
Disconnect the external audio device from TV and listen for audio from the TV’s built-in speakers. Under Audio or Audio Settings on the on-screen menu, set TV Speakers to On.
Update (05/10/2016)
Since that does not change anything, follow that attached flow sheet. I've found that the audio IC in most TV is of inferior quality and has a tendency to fail.
It is possible that due to a failed IR board your Television just does not receive signal for the volume up."
I was having the same issue with the sound on my Vizio TV and nothing I tried worked, until I accidentally unplugged my Cable box. When I plugged it back in the sound came back and it has been fine ever since. Still not sure what the issue was but I'm just glad that it is fixed. Hopefully this will work for you!
The sound on my Vizio tv just randomly stopped working one day. I tried all the troubleshooting solutions but they didn't work. I even checked to see if the tv speakers were set to on in the audio menu, and they were, so then I grabbed my speaker bar and hooked it up to the tv and the sound still wasn't coming through on the speaker bar. I then went to the audio settings on the menu of the vizio tv again and it showed that the tv speakers were set to off this time so I turned them back to on and the sound was working on the tv again! Hope this was clear enough and helped some people that have tried everything else..
I had the same issue with a Vizio E Series tv. I tried the advice read here in disconnecting the power supply to the cable box. It didn't work. I then unplugged the TV and the sound returned after plugging it back up. The Vizio app for Android required resetting. Not sure what caused the problem.
We have had this same problem. Off and on for years, mostly when we were gone for a time and came back. Resetting everything (cable box, tv, etc) seem to work. Then one day the sound went off in the middle of it working. resetting did not work. We were told it was most likely the main board. We found a main board on ebay. Could not find one anywhere else. We replaced the board. Still no tv speaker sound. I told my husband to try to turn the volume up on the tv and not the remote, he looked at me like I was nuts! I read this in one of my many searches. Guess what? The sound came on, and now the remote worked too. Then about 10 minutes in, the sound went off again. Vizio obviously has some kind of glitch and they must be aware of it because there are 100’s of people with this problem. and not just with my model. Vizio does not make 3D tv’s anymore and neither does anyone else, we have over 200 3D movies so we were bound and determined to keep this one working. Well now we have an extra main board. We have model M3D650SV purchased in 2012 . When I try to use the app to watch Netflix or Hulu, no sound, so I watch Netflix and Hulu from the DVD player so I get the sound through the Home theater system. We are able to get sound through our home theater system, so we will just use that. We tried to hook up a sound bar to the Video through RCA Video out, that didn’t work either. The Home Theater system is the only way we get sound now. So if that is an option for you, at least you’ll get sound.
Sound on vizio TV randomly not working? Go to audio settings and change speakers from “auto" to “on"!! Worked for me (after 2 months of unplugging and plugging back in to remedy the situation)
