A call on the main extension goes off or a loud noise appears when the main extension presses the receiver：
1、 Antennas are not placed vertically in open Spaces outside
2、The antenna base wire was broken during installation without connecting with the antenna pole
3、Low or unstable power supply
4、The main board of the extension may be damaged by a component
1、The antenna is placed outdoors towards the host. The problem received by after-sales service is caused by the fact that many customers don't bother to put the main extension outdoors.
2、Measure the on-off of antenna base with multimeter;
3、Test whether the power output DC port is between 12V and 13V with a multimeter;
4、Use the extension that can talk to the host to place the elevator room that can't talk to indicate that the extension is broken.