If it is still working, your unit apparently pre-dates the models made with the automatic "death-after-seven-years" circuitry. To be safe you should probably replace it even-so. *Disclaimer: I am not a lawyer, despite the handle. Words to live by: "Every creative act results from a sudden cessation of stupidity." -Edwin H. Land, inventor of the Polaroid Land Camera"The problem can always be solved with the materials in the room." -My college Physics Lab Instructor