NEC DTU 16D 1A not ringing

Yes, the NEC DTU-16D-1A can be used with a standard PSTN line. You will need to program the phone system to recognize the PSTN line instead of the ISDN2 line. Here are some steps you can take:

1. Access the programming mode on the NEC Xen Alpha system by pressing "Speaker" and then "7" on the main phone.
2. Enter the system password, which should be provided in the user manual or by your system administrator.
3. Press "Speaker" and then "3" to enter the line programming mode.
4. Scroll through the line options using the arrow keys until you find the option for PSTN. Select this option.
5. Save your changes by pressing "Speaker" and then "Store".

Once you have completed these steps, your NEC DTU-16D-1A handsets should be able to connect to the PSTN line and function properly.

In the link

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Manual

Dtu-16D-2 Tel - NEC Electra Elite IPK II System ... - ManualsLib

https://www.manualslib.com > manual > Nec-Electra-Eli...
NEC Electra Elite IPK II Manual Online: Dtu-16D-2 Tel. This digital Multiline Terminal has 16 programmable line keys (each with a 2-color LED), ...

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  NEC 16D and 8D Quick Start User Manual - ManualsLib

  https://www.manualslib.com > ... > Telephone
  View and Download NEC 16D and 8D quick start user manual online. Multiline Telephone. 16D and 8D telephone pdf manual download. Also for: Dth-32d, Dth-16d, ...
  
  

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Some phoses have an option to ringing called mode. Maybe it is set to some muted mode?

Ringing is assigned in system programming, very little chance it was changed by mistake. If Do-Not-Disturb was turned on, that could make a phone stop ringing. If it's just one line on a phone, maybe the system got put in night mode by mistake and night programming isn't identical to day ring. If you have direct access to the phone line check it for dial tone. Often virtual lines are used and you can't check for direct dial tone. On very rare occasion the ringer stops working, which can't be fixed.

samsung mobile

Might be that the Do Not Disturb is on. Try pressing feature 69 then the feature key again.

This phone is a proprietory digital phone that only works with a KSU. You would need an IPK or Elite phone system to make it work. You would also need to program it. This is a business office system and that phone will not work unless it is plugged into the system.

During an incoming call try holding the up arrow on the volume key. That is the only way I know to increase or decrease the volume of the ring. The phone might also be set on DND. in which case you have to Press feature dial the DND cancel code 69 press feature. If note look for you user guide here. http://www.neccare.com/cng/docs.nsf/Lib3?OpenView&Start=1&Count=100&Expand=6.13#6.13

Jennifer209, if you press FEATURE + the button VM is pre-programmed on what does it display? It should show the extension number pilot to VM. If you call it directly, what happens? If you get no answer calling it directly, your VM may be down.

Kaait, is it getting into the VM that's the problem, or doing things inside the mailbox that is the problem?

This is a phone system phone and each station you want to ring when a certain phone line rings has to be programmed into the system. This is not something you can change at the phone itself. You will either need to pay a company to make programming changes or locate a programming and installation manual for your phone system (not the phone) and try to re-program it yourself. If you have not done this before it will not be easy but it may be worth the effort so you can continue to make your own changes instead of paying someone $200 per hour to do it for you.

 

There is also the remote possibility your phone's ringer is broken. You can try swapping your phone with another of the same type and model to see if it will ring.