The DNAM is the "Digital Natural Audio Module" - it's a multichannel amplifier with built-in digital signal processing. It is a component specially designed for use with Cisco/Legacy TANDBERG codecs.
Below are a couple of supportforums articles with troubleshooting info and pictures, so that you can "put a face to the name" (or part-number!)...
Supportforum article/doc on how to replace a DNAM - it has some good pictures and will give you familiarity with what the DNAM looks like: https://supportforums.cisco.com/document/64791/cisco-tc-style-profile-dnam-replacement
Link on troubleshooting (they occasionally blow fuses if the units are turned off a lot - they are meant to 'go to sleep' but some users insist on unplugging!): https://supportforums.cisco.com/document/9877576/t3-telepresence-troubleshooting-digital-natural-audio-module-dnam
