Dial tone absent

Dial tone absent on external lines 1. Use Button Inquiry (≤•‚) to display the number of the external line you are testing. 2. Check for dial tone using a test telephone at the connections for the external  line on the distribution block. 3. Make sure that a Trunk Cartridge for the line is properly installed in the ICS or Trunk Module. 4. Make sure that the Trunk Module fiber cable is properly connected to the Expansion Cartridge on the ICS. Refer  to  Problems with trunk cartridges service  on page 611 and  Trunk or Station Module down  on page 619. 5. Run a Maintenance session to ensure that the line is not disabled. See  Port/DN status