Summary
No sound and/or video from a door station to the JP-4HD video sub master station, but sound and video works on the JP-4MED video master station.
Solution
Cat-5e/6 cable connection between the JP-4MED to the JP-8Z or JP-4HD has loose or broken wires and the RJ-45 connection is not making contact with all pins.
Bench test the JP-4HD next to the JP-4MED or JP-8Z using a verified patch cable. Testing of existing cable and connection is also recommended (see RJ-45 pin out below).
When installing RJ-45 connectors use either EIA-TIA 568A OR 568B standard. Crossing between standards will cause system failure and possible damage.
