The S1, while feature packed, is a consumer level digital camera that has a very short designed lifespan. I'm guessing it's over 5 years old, and most consumer level cameras are meant to last only 2 to 3 years. The first (and most expensive to repair) component to fail is usually the sensor, which sounds like the issue your camera has. Take it to a repair center that offers a free estimate. If it's over $100, it's probably best to replace it.
