Reasons why your phone may have stopped working after an office change.
Depending on your location, it is possible the ethernet jack needs to be activated. Contact your department IT for activation. Provide the room number, building, and the jack number.
Whenever you move, allow the phone to lock, or turn off your IP phone, log in again with your Active Directory NetID and Lync PIN. If you forgot your information, visit https://dialin.uillinois.edu/ and check your information. You will be able to reset your PIN from this website, even if you don't know your current PIN.