I have 4620/4621/4625 sw ip phones that were on a definity, i want to input new parameters into the phone to work on ip office, when i plug these phones in, it goes to dhcp and vlan, but nevers displays press star key to program, just counts to start dhcp. All keys are disabled, just beeps when you press them. can't press the mute key and enter codes for reset or test etc functions. It's like the phones are locked. Thanks for any help!