Our s15 adventure continues. This morning we shipped the (2) S15's that failed on 240v to the CA repair depot. This afternoon 10 more S15's arrived from BitMain. We put them on the 208v rack at the office. Of the 10, 7 work perfectly and 3 will not show up on our network despite all efforts and troubleshooting. Can't figure it out. So now I have 13 S15's running, 2 going back for PSU, and 3 that boot up but won't communicate with the network. I wish I could get ahold of a couple of spare PSU's and controllers for these guys. They aren't selling S15 parts yet, are they?
Are you getting both blinky lights from the Ethernet ports?
One thing, which I assumed was because I swapped an Ethernet cable from an A4+ to the T15, is that when I powered up the T15 is it stole the IP address from the A4+. Given this may not be an isolated incident caused by my switch, are you using static IPs or dhcp? If DHCP, you may want to move all the existing miners to static IPs and see if the missing miners start showing up.