If the display is blank,
Something has happened to the controller.
Sounds like the main board has experienced a failure since the power supply appears to be functioning properly.
It could be possible that the power supply is not producting the needed 24 volts if the rain sensor is capable of turning on at a lower voltage, but that really is a long shot in the situation.
The controller needs the 24 volts, but it could be possible the rain sensor lights at much less.
In order to verify, a test would need to be performed and verify the voltage.
If 24v, the controller board has failed and if less, then a new power supply is needed.
Controller boards are too difficult to obtain, so changing complete controllers is what manufacturers recommend
TORO has a 3-5 year limited warranty on the product:
During such warranty period, we will repair or replace, at our option, any part
found to be defective. Your remedy is limited solely to the replacement or repair of
Return the defective part to your local Toro distributor, who may be listed in
your telephone directory Yellow Pages under "Irrigation Supplies" or "Sprinkler Systems
or contact The Toro Warranty Company P.O. Box 489, Riverside, California,
Phone(NNN) NNN-NNNNfor the location of your nearest Toro distributor or outside
the U.S., call(NNN) NNN-NNNNbr/>
One last check to do, is disconnect the rain sensor receiver yellow wires and see if the controller starts to function again.That would mean that the power supply is weak and cannot power both the units.