What to do if all AT&T Conference System voice terminals have no lights and no dial tone?
- GGabrielle DouglasAug 19, 2025
If all AT&T Conference System voice terminals have no lights and no dial tone, first, try turning the control unit off and then back on. If that doesn't work, ensure the control unit is not plugged into a switch-controlled outlet. Test the power outlet with another appliance. Lastly, with the power off, remove and reseat each module and cartridge in the control unit, ensuring they are secure, then turn the power back on.