I have an R420 that has redundant RYMG6 PSU installed. One is at version "07.15.7E" and the other is at version "05.07.0D". I downloaded the 32-bit DUP "Power_Firmware_JWTNW_WN32_07.15.7E_A01.EXE" from this link.
I was looking in the idrac lifecycle log and noticed the following detail on the "Job Failed" status message.
RED004: Job failed. 2018-03-19T11:51:37-0700 Log Sequence Number: 30906 Detailed Description: The Job failed to execute due to an unknown error. Recommended Action: Check the uniform resource identifier (URI), target path and make sure the repository server is available.