You shoild connect the phone to some hist that can tell you if it getting IP address via DHCP, the HDCP reply includes "option 66", so the phone reques a file (gkdefault.cfg) via TFTP. If so, it is possible to prepare this file to reflash the phone. You need to download a latest image and the "BMP utility" from t912 area on CCO.
But please confirm first the phone is getting an IP address an makes TFTP requests. If you are not sure aboyut the current TFTp server, I suggest you connect a PC with TFTPD32 that is a free download.