My 6 year old Rain Dial automatic sprinklers stopped working. The electrical outlet is okay. The window displays the current time, day, etc. Nothing happens on the regular set watering days. I can't even make a section go on with manual operations?

Is there any easy, quick, trouble shooting things I can do, or just replace it. It replacing it a DIY job?

Check to see if there's a rain shutoff installed. They are used to prevent the sprinklers from working during rainy periods.
If there is one make sure that there isn't any water in it.

Thanks for your response. I think, hope, the nice folks at the irrigation store were correct. They said the "timers" have a 5 year warranty, so at 6 years sometimes the timer just goes out? I just bought a new "timer" and installed it.