If I have a bad LS/DS Analog Trunk Cartridge can I still program the lines on the phones? System is currently at the DR5 with square configuration. I'm trying to add outside lines 3-7 to appear & ring on buttons 3-7. I checked programming however the buttons still remain as the square configuration? At default lines 1 & 2 appear & ring perfect. I think button 3 is call xfer, 4 is forwarding & so on.. Thanks for the assistance!!