Sony TVs with no sound or sound-adjustment problems often benefit from a basic troubleshooting process. If the basic troubleshooting does not work, however, the problem may exist within the speaker hardware. In this case, professional repair or speaker replacement is not uncommon.
Run a Power Cycle
A quick reset through the power cycle can work magic for a television with sound problems. It works for a number of other short-term, intermittent problems as well. Unplug the TV from the power outlet and wait several minutes while the power leaves the system. Consider running a simultaneous power cycle on your cable box, external audio and other connected systems at the same time.
Return everything to power and turn on the television. Test for audio to see if any problems continue. Make sure you are using the Bravia internal speakers only because an external speaker system that experiences issues requires a different approach to troubleshooting. If the power cycle fails, a factory reset is another option, but run through the sound settings first to prevent losing any custom settings applied to the television over time.
Adjust the Sound Settings
The actual sound settings can cause issues within the sound system. Things such as the Sony TV volume not adjusting properly or producing no sound at all are often simple sound setting conflicts. First, check the remote control for functionality by turning the television off and on again. If the remote is operating properly, press the sound up button to increase the volume.
If the volume change is not evident, press Mute to ensure the sound is not muted. Next, check the audio jack for a cable. Headphones or external audio cables can transport the sound away from the speakers and through the external cable system. Unplug any external audio systems to isolate the problem to the built-in speaker system of the TV.
Next, access the settings menu on the television and locate the Headphone/Audio Out option. Make sure it's set to Audio Out. Move to the MTS settings and use Main or Stereo as the primary option. Also, check the main menu and turn the speakers to On to ensure they are activated. Lastly, turn off the surround sound if no external system is attached to make the internal speakers the default use setting.
These simple sound settings ensure the speakers are the primary sound source and should resolve any issues not specifically related to the hardware.
Running a Factory Reset
To run the factory reset, press the Home button on your remote and choose Settings, followed by Storage and Reset. Select the Factory Data Reset option and erase everything to restore the television to the factory default settings. You lose any custom settings, but the sound functions return to the normalized settings as if the television is brand new.
If the factory reset does not solve the problem, you may have an issue with audio cables and physical speakers that cause the sound malfunctions. Pursue the customer support channels at this juncture.
Inspect the Audio System
The physical speakers are integrated into the television, and no external cables are present. If the speakers in the Sony Bravia are physically failing, warranty work or replacement through Sony or a local repair service is the only viable option.
The other workaround is through an external speaker system. Add a soundbar or surround sound speaker system to eliminate the stock speakers. In many cases, this becomes an upgrade to the sound system and overall sound capabilities. Use new quality cables and check all connections to ensure the external speakers function as intended.