pool problems

I have a hayward salt in ground system.  My salt cell 9is a t-15,  The electronic management system is hayward aqua rite.  One year ago (and I believe I bought it from your store), a new ncell, new PCB, and new display board.   Before I start tearing things out and replacing parts, please provide me with some advice.

The on light is on.

low salt light is steady

clean cell is steady

the readout reads: SLo

My salt level (per the pool store) is 2900.

ANY SUGGESTIONS???

Thanks,

mpallen@windstream.net