If your iPhone 4S headphone jack or mute switch is giving you issues, a DIY repair on the cable that handles those functions can remedy the problem. Symptoms typically include audio cutting in and out when headphones are plugged in or no sound at all. The mute switch can also face issues where turning vibrate on or off results in no response or the switch itself being loose. These problems don't typically involve the actual mute switch, but the cable that lies underneath it.
Regardless whether you're having headphone jack or mute switch issues on your iPhone 4S, this guide can walk you through how to get both functions back in working order again.