Thanks all for the help, here's an update....

After hours of trying and failing I gave up. Miners sat turned off for over 48 hours as I was out of town. Came home and powered one up and it worked. No idea why. Got the second one working too. I did nothing different. I'm stumped but happy they are working. At the moment I can only get one to run at a time as they're interfering with each other on the network. I'll work on that next.