I have a customer with a Comdial Executech system. All of the phones are 6706X except one and it is just an intercom. This intercom is the one that has died(lots of static and sounded like it was underwater before it went dead). I am trying to locate a replacement for this. The only markings I can find are "MK-008PC Rev. D" on the board itself. Thanks for your help.

Doug