# Troubleshooting from error codes

Dial tone cannot be detected when dialing.

• Plug in the phone and check for a dial tone, continuous tone, or intermittent tone from the switch.
• Check if it is PSTN line or PBX line. In case of PBX line, change connection line setting to PBX and check again.
• If you can hear the dial tone but can not detect it, record it and check the signal and adjust the detection method in [FAX Maintenance Mode].

  
  At this time, the [OFF] setting of dial tone detection has a risk of false detection. Avoid as much as possible.

Line voltage was present before making a call (when on-hook), but lost when calling (when off-hook).

Check whether the LINE port and the EXT  port are connected in reverse or check the telephone connection

No line voltage before calling.

• Check that the telephone line is correctly connected to the LINE port.
• Connect your phone, hear a dial tone and see if you can dial and place a call.
• Check the line voltage with a tester. (DC48V when on-hook)

Busy tone detected when dialing.

• Check that the phone number is correct.
• Check if another signal is incorrectly detected as a busy tone.
  If a false detection has been made, record the signal and check for the false detection.
  Turn off the busy tone detection function or adjust the detection method in FAX Maintenance Mode.

Fax signal from destination machine cannot be detected after dialing.

• Check that the phone number is correct.
• Check if the fax signal is returned from the other party.

A communication error occurred after connecting the line.

• Output the communication management report and check the error occurrence status.
  In a fax using a subscribed telephone line, a communication error may occur if the state of the grasped telephone line is poor, and if redialing is performed by automatic redial, a good telephone line can be grasped and normally sent.
  If there are extremely many communication errors, it is checked whether the error has occurred at a specific destination or whether there is any tendency such as a time zone.
  Since a communication management report is necessary for trend survey, a communication management report is automatically printed. Have the customer keep it.
• Output the protocol monitor log of the communication at the time of error occurrence and investigate where in the communication the error occurred.
  In the FAX Maintenance Mode, select the "Error only" or "Auto print" option as needed.
• Obtain communication recording data at the time of error occurrence and investigate the error occurrence status.