So, update. we got 2 more S15's in today. These are 2 of the 27TH models. Put them on the rack and they came right up on the network. So for the 3 that were giving us trouble, I took a laptop and a little VPN router that I have and direct connected each unit to the laptop via the router, then ran WireShark and found the IP the S15 was broadcasting. That got me in, and I programmed a static IP to each S15, reconnected, and they came up just fine on our regular LAN. Not sure what the issue with getting a DHCP assignment is for these units (they are running the same firmware versions as other units that worked fine to begin with). In any case, have 18 on the rack now running 100%. The two units that had the PSU problem at 240v already went back to bitmain for warranty repair.
Onward and upward.
Onward and upward.
Maybe your dhcp server is having trouble? That's one more reason i would recommend to set networking manually in all miners. Perhaps the only moment you'd need dhcp is when its brand new and you need to log in to configure it the first time into a proper manually set address, like you just did