Thanks for the reply. It was cleaned in May. I took it down yesterday and had it checked - the cell was fine. The salt read 2900 and the pool store had it at 3000. After a day with no lights on the display, the pool store had me "reset" the unit which took my salt reading to 0. Eventully, the salt reading climbed to 2200. then, Sunday morning when the pump kicked on, the power light came back on with "low salt" and "check cell" continuously lit. After turning it on and off, sometimes no lights are lit, and sometimes the power, low salt and check cell are lit. Right now, those three lights are on.