From the R730 manual:     It looks like you'll want to consider replacing the PSU with a supported unit.
I have a R730 server, it does turn on for a few seconds and then power off. the PSU Is flashing in Green. I have used a DELL R720 PSU for this server, is there any issue for doing this?PN 06W2PW
Shutting down after power ON PowerEdge R730