Carnegie Mellon University

Phone Troubleshooting Guide

Follow the instructions below to troubleshoot your Centrex phone before you request a repair.

If you hear static on single-line set (Comdial, M9316), do the following:

  • Verify that the connections are tight at the outlet and set.
  • Verify that the connection to the receiver is tight.
  • Try another set, if available.
  • Shake the receiver and line cord to determine if the static increases or decreases.
  • Disconnect any other equipment (e.g., an answering machine, etc.)
  • For the M9316 set, follow these steps to "power cycle" and reset the phone:
    1. Unplug the line and power cords under the phone for at least 30 seconds.
    2. Plug the line and power cords back in.

If there is no dial tone on a single-line set (Comdial, M9316), do the following:

  • Verify that an order is not in place to change, move, or disconnect the line.
  • Verify that the physical connections are tight at the outlet and set.
  • Try another set, if available.
  • Disconnect any other equipment (e.g., answering machine)
  • For the M9316 set, follow these steps to "power cycle" and reset the phone:
    1. Unplug the line and power cords under the phone for at least 30 seconds.
    2. Plug the line and power cords back in.

If a single line set does not ringing (Comdial, M9316), do the following:

  • Comdial set: check control on bottom of the set.
  • M9316 set: check the volume control buttons at the bottom of the set.

If you hear static on a Meridian business set, do the following:

  • Verify that the connections are tight at the outlet and the set.
  • Verify that the connection to the receiver is tight.

If there is no dial tone on a Meridian business set, do the following:

  • Verify that the connections are tight at the outlet and the set.
  • Check to see if all numbers on the set are dead.
  • Verify that an order is not in place to change, move, or disconnect the line.

If the display or the speaker is not working, do the following:

  • Verify that the power cord connection is tight at the wall outlet and at the phone.
  • If the power cord is plugged into a power strip, confirm that the power strip is on and operational.

Computing Services does not service answering machines. Refer to the retailer or the manufacturer of the device for repair information.

Repair Request

IMPORTANT! Before requesting a repair, refer to the Phone Troubleshooting Guide above to try to resolve the problem yourself. However, if the problem persists, call the Telecom Service Line (412-268-8500) with the following information:

  • Telephone Number To Be Repaired
  • Building Name
  • Room Number
  • Contact Name
  • Contact Phone Number
  • Alternate Contact Name
  • Alternate Contact Phone Number
  • Phone Set Type (Comdial, Meridian)
  • Problem (e.g., static, no dial tone, etc.)