Jorge Luis Rincon Suarez this could be an issue with the main board. The audio processing is done on that board. You want to check for bad caps or anything else looking damaged. It would help if you can tell us the exact model of your TV and post some good images of your boards so we can see what you see. Use this guide [guide|21499] for that. You can always try and connect some different speakers and see if that makes a difference. The other thing to try would be headphones. Let us know what you find.