: Attach the camera and power supply wires to the back of the monitor following the polarity guide above.
| Problem | Likely Cause | Solution (per manual) | | :--- | :--- | :--- | | | Video wire reversed or broken. | Swap the wires on Terminal 4 (Video) and Ground. Check continuity with a multimeter. | | Humming or feedback in audio | Ground loop or untwisted wires. | Ensure Terminal 2 (GND) is solid. Use a tighter twist on the audio pair (Terminal 3). | | Monitor does not ring | No power to door station or broken audio wire. | Check voltage at Door Station Terminal 1 (V+) to Terminal 2 (GND). Should read ~12V DC. | | Door unlock doesn't work | External lock power supply failed or relay not connected to NO/C. | Verify your external 12V supply is working. Ensure wires are on "NO" and "COM," not "NC." | | Image is wavy or rolling | Distance too long or interference. | Reduce cable run to under 100m. Keep CAT5e away from AC power lines. | commax cdv-70n installation manual
The is a high-performance 7-inch color video door phone designed for secure residential and commercial communication. To ensure optimal performance and longevity, follow the steps outlined in this installation manual, which covers mounting, wiring, and safety precautions. 1. Preparation and Safety Precautions : Attach the camera and power supply wires
Since the CDV-70N provides a dry contact only, follow this diagram from the manual: Check continuity with a multimeter
The manual emphasizes that the door station must be protected from direct rain and sunlight where possible.
