Unless you try toggling the "External" or "Mute" feature within the Audio menu, I don't have any further recommendations. It may require repair, and if that's the case, you can do that with your current tech or by calling 800-SAMSUNG.
I have had a Samsung LCD TV model LN40A530 for about a 1.5 years now. Two days ago while watching TV suddenly there was no volume. At first I assumed it was the show, but when I changed stations there was still no sound. I then tried raising the volume & where the slider is on the TV that shows the volume control, at the top of the display is a set of headphones. I assume this means the TV thinks there are headphones plugged into the jack, but I have never used headphones on the TV.
- I tried doing a sound reset from the menu option - still no sound
- I tried reseting the TV to factory settings by holding down the "EXIT" button on the remote and going through the steps - still no sound (I did this at the request of a Sumsung phone service rep)
- I tried plugging headphones into the headphone jack on the TV (I did get sound through the headphones) and unplugging them - still no sound through the TV speakers
I'd appreciate any help or suggestions as my TV is off warranty. The Samsung phone service rep suggested I take it in for repair, but I figure there might be something else to try first. I temporarily have it hooked up to an old amp & speakers that I've had since the 80's.