I have an Aqua Rite electronic chlorine generator-T cell 9. It has been working well for over 7 years. It worked fine all winter but suddenly isn't procuding any chlorine. I have inspected it on a regular basis and cleaned it a number of times even though I have never seen any scale buildup. The light inspect cell has been flashing for awhile. My salt level is fine. Does anyone know what the life of this cell might be?