Wrong power adapter cause indicator of FXS lines always was lighted. (The line indicator on IAD104H was green always.)
Usually these indicator will lighted only when this phone was pickup or was talking.
1. Login to WEB of IAD104H, choose "Diagnose > System information > download" to download the system configuration and alarms. After checking we found there is no abnormal.
2. Check the power supply : customer use the power adapter as below photo, from which we know the output of that power adapter is 5.0V/2.0A, but the right power adapter of IAD104H should be 12V/1A.
Ask customer change to the right power adapter, problem solved.