Hi ctvader,
The OID for EX Power supplies starts at .1.3.6.1.4.1.2636.3.1.13.1.6.2:
dfex@EX4200-VC-Core> show snmp mib walk .1.3.6.1.4.1.2636.3.1.13.1.6.2
jnxOperatingState.2.1.1.0 = 2
jnxOperatingState.2.1.2.0 = 2
jnxOperatingState.2.2.1.0 = 2
jnxOperatingState.2.2.2.0 = 2
jnxOperatingState.2.3.1.0 = 2
jnxOperatingState.2.3.2.0 = 2
This is the output from a three switch virtual chassis - the number in bold is the node (1 for node0, 2 for node1, 3 for node2 etc) and the underlined number is the power supply (1 for primary, 2 for secondary). So if you just wanted to look at state of node2's (the 3rd node) secondary power supply for example, just add .3.2 to the end:
dfex@EX4200-VC-Core> show snmp mib walk .1.3.6.1.4.1.2636.3.1.13.1.6.2.3.2
jnxOperatingState.2.3.2.0 = 2
The actual value of Operating State can be from 1-6:
1- Unknown
2- Up and running
3- Ready to run, not running yet
4- Held in reset, not ready yet
5- Running at Full Speed (valid for fans only)
6- Down or off (for power supply)
7- Running as a standby (Backup)
Hope this helps