Question
Controller and sprinkler system is over 15 years old.

The display on the controller is not fully visible -- all unrecognizable and partially lit.

Many days it does not go on.  We set to manual -- and still
does not go on.  One day last week, we did the same process again and the manual override worked -  but only the one time.

Please advise.

Answer
Hi Helen

This are a pretty old model, as today we can't find spare parts You can replace it with a Rain Bird ESP modular the basic unit (4 stations) cost about $ 80, if you are using more than 4 stations in your 476PRI you will need an additional module, costs about $ 27. In You want something cheaper you can try the Orbit Lawn Master.
Regards
Guillermo