Does anyone have an idea what would cause a no audio on some of the phones in the first cabinet? You can hear the caller but they can't hear you. This is a two cabinet system. Had a problem with the lower (1st) cabinet locking up. Displays worked but not any of the buttons. Reset the system, reset the dvr cards the the first two ulds with phones started working fine. In the next set of powered slots only the first 8 of 16 ports work with audio both ways. The ons card will not break dial tone. I have power modules in all three positions. moved the card around but same problem no matter where I place the cards in the slots on the cabinet. I replaced the uld card. Same problem. I moved some of the phones to a empty port on a different card and they worked fine. Any ideas? S400 release 3.13.