FYI - the only info I could find about sensor life expectancy was this answer from Yahoo, keep in mind where it's coming from
Q&A: How Long Will Your Camera Last?
For a time on the rec.photo.digital newsgroup, there was a thread about a camera becoming defective and progressively underexposing pictures more and more. This thread generated a lot of conversation about the expected lifetime of CCD and CMOS sensors in digital cameras. Many folks said, "If you get three years before the sensor goes out, you're lucky." Other comments were along the lines of, "You don't buy a digital camera, you just rent it until the sensor goes bad--which is inevitable." Have you heard anything about the image sensors they are putting in these things? What type of life expectancy do they have?
--Mike Tinsley, New York
That's an excellent question, Mike. I didn't know the answer, but I was intrigued--so I posed it to Kodak. A representative obligingly stepped up to the plate.
Helen Titus, a spokesperson for Kodak's Image Sensor Solutions--the division that manufactures the CCD sensor for the company's digital cameras--told me that Kodak performs "accelerated life testing" on its sensors by running them at high temperatures for several thousand hours, right to the point of failure. Engineers, she says, can translate that into an expected lifetime for the sensor in normal operation at everyday temperatures and more typical on-and-off usage.
"We find that the sensors last for tens of thousands of hours in continuous usage without any degradation to their ability to capture photos," Titus says. "That adds up to many years of normal use. The CCD is not the component that will fail first."
Martin Reynolds, a digital imaging analyst at Gartner, agreed with Kodak's assessment. "Those sensors are pretty robust little devices with no long-term failure mechanisms." His only caveat? One I've written about before: "If you expose the CCD directly at the sun, you might cause some damage. But even then it would take an extraordinary amount of energy to cause deterioration."
So, while it's always possible for an image sensor to fail early or behave improperly, it sounds like the majority of digital cameras shouldn't suffer from premature image degradation due to the CCD or CMOS sensor.