Brand: NEC
Category: Other
Document Type: Manual
Language: EN
Available Languages: EN , ES
Manual for DT400/DT800
Uploaded: Nov. 21, 2025, 9:21 p.m.
Warranty Information
Warranty information is not provided in this manual.
Phone Operation Summary
Making Calls: Lift handset or press Speaker, dial access code (e.g., 9), then the phone number. For internal calls, dial the station number directly.
Answering Calls: Press the flashing MULTILINE APPEARANCE key, then lift handset or press Speaker.
Holding Calls: Press Hold to place a call on hold. Press Hold twice to lock the held call to your station. Retrieve by lifting handset or pressing Speaker, then the held line.
Transferring Calls: While in conversation, ask the party to hold, press Transfer, dial the destination extension, and wait for answer.
Conferencing: Ask party to hold, press Transfer, dial the desired number. Once answered, press Conf.
Speed Dialing: Press a Speed Calling key directly, or press Speaker then the Speed Calling key. To program, press Feature, the Speed Calling key, enter the number, then press Feature again.
Call Forwarding: Use CF-AllCalls to forward all calls or CF-NoAnswer for busy/no answer. Press Speaker or lift handset, press the appropriate key, dial destination, then Speaker or hang up.
Troubleshooting and error codes
| Problem | Possible Cause | Solution |
|---|---|---|
| No dial tone | Handset not lifted or Speaker not activated. | Lift handset or press Speaker. |
| Call not connecting | Incorrect number dialed. | Verify and redial the number. |
| Call forwarding not working | Incorrect destination number or key pressed. | Verify settings and press the correct call forwarding key (CF-AllCalls or CF-NoAnswer). |
| Unable to transfer call | Destination station busy or not answered. | Re-attempt transfer or use alternative method. |
| Speakerphone not working | Mic button not activated. | Press the Mic button; its LED should be lit. |