1. The extension can call but there is no video (the screen is not lit)?

 

a. Check whether the K line on the power interface of the host is connected to the G line; b. If the two ends of the extension terminals 7 and 8 are connected.

 

 

2. The extension can call but there is no video (screen is on)?

 

Check if the video cable from the host to the extension is reversed.

 

 

3. The host calls the extension. If the extension only rings, it will be disconnected.

 

a. Whether the extension is programmed as a secondary extension; b. Whether the power supply voltage of the extension is normal (not less than 15 volts during operation); c. Try again after replacing the host or extension.

 

 

4. The extension can call but cannot monitor the host?

 

Whether the host number is programmed as a secondary host (the extension cannot monitor the secondary host).