[Al Skierkiewicz]

In nearly 100% of the cases, there is a whisker touching the negative and positive 24 volt leads together. Pull the connector out of the PD and see if the 24 light comes on and if you measure 24 volts at the connector. That will tell you if the PD is OK. There is some protection circuitry in the PD that could have failed if you had somehow exceeded the power supply specs. If you are using 24 volt solenoids and therefore are using the Crio power supply in two places you need to check all wiring. If the PD is good, try powering the Crio by itself (i.e. remove the power to the solenoid module). If that is OK then look to something wrong in the solenoid module wiring.