As with most television manufacturers, Sony designs its sets to last for years under normal conditions. If a problem arises or the TV isn't working the way it should, it may be in need of repair, but you can try steps at home first to see if the problem is minor and fixable.
Problems from bad cable connections to improper video settings, poor signal sources and outside interference can affect the picture quality of your Sony TV. Double-check the connection to the cable/satellite receiver, antenna or other component. Are the cables connected securely and to the right inputs? Is the TV on the correct channel? Is the component turned on? Try another component input to see if the picture improves. Turn off any outside devices that can cause interference and see if any bright lamps or windows are causing a glare. Turn off the TV and plug it into a different outlet or surge protector.
Some issues can be corrected or adjusted by accessing the menu and settings for your particular model. If the TV is a projection screen, adjust the convergence of the picture tubes, either manually or with the Auto Convergence feature. Turn on the Digital Noise Reduction to cut down on interference or the Digital Reality Creation feature. Adjust the sharpness, brightness and contrast to see if that improves the picture. If you see black bars at the top and bottom or both sides of the screen, adjust the aspect ratio. Check the picture resolution settings if you're not getting a clear enough picture from an HD channel and check those settings on the cable/satellite receiver as well.
If the picture is on but the audio is faint or not working, check the input and cable connections first. Turn the volume up manually or with the remote control and do the same with the cable/satellite receiver if it has separate settings. The TV must be set to "Tuner" and not to "Video" to be able to change audio settings. Change the channels and try using the TV with a different input to see if the audio is noticeably different. If the audio and video are out of sync, turn the TV off and unplug it to let it cool down for a minute. Turn it back on and reset it to the original setting if it persists. Use the audio menu to adjust the balance if one speaker is louder than the other and check that the TV is set to "Stereo."
If the remote control is not responding, first check the batteries and replace them if necessary. Point the remote directly at the infrared sensor on the TV and check that nothing is blocking the path. Clean the surface of the remote and sensor with a damp cloth. Use the Auto Program feature in the menu if certain channels cannot be viewed; this will locate all available channels. Consult the owner's manual for your model for more tips, definitions and settings, or visit the support page on Sony's website and enter the model number. If the problems persist after going through these steps, your television may be in need of service.