Question
I have been having problems with my sprinkler actuators turning on over the years.  In the last month, I cant get the unit to turn out manually.  This unit is probably 20 years old, never had a problem.  Could it be the fuse, power supply, etc.?  How do I check out these parts?

Answer
Hi Berry,
Check through fuse, take it out see trough the glass, if the wire looks broken replace it.
Measure the power at the screws marked T, should be 24V, if it is less the transformer is defective.
Turn on zone 1, and measure the power at the screw 1 and the screw C, should be 24V, if is less the controller is bad. Repeat for each zone.

Regards
Guillermo