I have a great picture but no sound?
Hmmm, Your question (I have a great picture but no sound?) is extremely vague. Let's check the obvious first, and proceed to the obscure...
With your Remote Control, turn up the TV volume. - Does the numeric or gas-guage type of audio level display on your TV? If the audio level does not display on your screen you might have a problem with your remote control. Try to adjust the volume with the volume adjust buttons or sensors on the TV, usually found on the rear side of the TV close to the right or left side. Sometimes these controls are on the front, top, or bottom of the TV frame.
Next let's check the source of the picture, and how the sound goes from the source to your TV. If the source only outputs sound from the analog sound jacks (usually red and white, and labeled Audio Out) you will need to connect audio cables from the source's Audio Out Jacks to the Audio In Jacks of your TV.
If your setup uses HDMI cables, ensure the cables are seated properly on BOTH the source device and the TV. You COULD have a problem with the HDMI cable that only affects the sound, but replace that cable as a last resort. Ensure the SOURCE device (such as a satellite TV or cable box) does not have the sound MUTED. (DOH!)
Next go into your TV MENU. Select SOUND (or AUDIO) and scroll through the features to ensure that the source of the sound input is the actual input you are using. Ensure the TV SPEAKER selection is enabled. Ensure that the digital optical output option is not selected if you are not using it. If your TV has an old-school headphone jack, ensure that a cable is not inserted into the headphone jack.
If you have another TV you can connect to your source, you can quickly determine if the sound problem is with your original TV or the source device. You might be able to also use another input device with your original TV to determine if the TV produces sound from this alternative source.
You might even hook up a cheap digital TV antenna directly to your TV's RF jack, if there are local TV stations you can pick up. If you can see a TV channel picture but no sound, then the problem will definitely be in your TV.
Inside nearly every TV is a circuit board dedicated to sound output. The problem may be on the sound circuit card or from the circuit board that is feeding the sound to the sound circuit board. Very rarely would the two speakers both fail at the same time... but a damaged headphone jack (caused by a foreign device that was jammed into the jack and removed) can cause this problem. If you have a damaged headphone jack and don't need it, simply remove the wires from the headphone jack and connect these wires directly to the speakers.
You can purchase a replacement sound card and install it pretty easily. If that doesn't fix the sound problem, you might need to replace the tuner circuit card.
Good Luck, and let me know if any of this helped you!
8 minutes ago