REF: http://www.rainbird.com/documents/turf/man_esp-tm.pdf
Have you checked the breaker? The wall outlet?
If power is at the wall outlet, then you can use a multi-meter to check power at the end of the power supply cord at the (24VAC) terminals inside the control panel - see Page 34. This link gives you the part numbers in case you need to replace: http://www.rainbird.com/documents/parts/part_ESP-TM.pdf
Also, check out the troubleshooting guide on page 36.