A few things to try (if this does not work then the tv may need parts and service):
1. Leave the tv on, locate the POWER cord for the cable box and unplug it from the wall outlet, wait 10 seconds and plug the power back in, watch the tv screen as the box boots back up. Check for sound, if needed goto next step.
2. Unplug the tv POWER cord for 3 full minutes, plug back in. Check for sound, if needed goto next step.
3. Factory Rest the tv using the Vizio remote:
- Press the MENU button
- Use the Arrow buttons on the remote to highlight the Help icon and press OK.
- Highlight Clear Memory (Factory Default) and press OK.
- Enter your parental control passcode. If you have not yet set up a parental passcode, enter the default, 0000.
- The TV displays, “Are you sure you would like to Restore Defaults? This will erase any custom settings.”
- Highlight Yes and press OK.
- Wait for the TV to turn off. The TV will turn back on shortly afterward and the Setup App will begin.
- Complete the setup and check for sound.
4. Connect something other than the cable box to the tv to verify if sound can be heard or not.
If you still have no sound then the main board in the tv needs to be replaced. If that is something you want to attempt then reply back here and I can help you (a meter and some previous electronics experience is required). If you are unable or unwilling to perform these operations then a repair shop should be consulted.
I am here to help you. Please reply back if you need clarification on any of the above, or even if you just want to say "thank you" :-)
In keeping with the design of this website, please be sure to click the 5 STARS or SMILEYS rating now. Doing so does NOT close the question or prevent us from continuing our conversation here. My livelihood truly does depend on your positive rating.
I understand news of a failure is upsetting but clicking the "bad/poor" rating does NOT do anything to fix your issue, nor does it issue you a refund.