Try factory defaulting the phones. Sometimes i had to do that several times before they came up
Hold down 1-3-5 at the same time. Then enter 456 for password.
Frank, did defaulting the handset resolve the issue? Thanks
defaulting one of sets resolved issue. Also found customers IT vendor had been on site and for some unknown reason had another DHCP server running on network. I statically assigned provisioning server in sets and then they registered. IT to disable other DHCP