Salt is Not Going Down

My Valve appears to be operating but the Salt is Not Going Down.
What could cause this problem?

The salt not going down could be due to many different reasons.

1 ) Valve is not regenerating due to a problem with Timer Motor or a bad gear in the timer assembly ( common in Autotrol Timer Assemblies ).
2 ) Salt may be Bridged ( become solid ) above water that is at the bottom of the salt tank.
3 ) If you have been using Pellet salt for many years you could have a lot of undissolvable residue at the bottom. This residue will not dissolve and also can block water flow in and out of the salt tank.
4 ) The Valve could be failing to draw the brine solution out and if you have a float shut off in the brine tank, it would be prevent the salt tank from overflowing ( which it would do if the float shut off was not there ).
5 ) The brine refill control could be clogged, prevent water to refill the salt tank.