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External power for 8434D digital phones - Knowledgebase / Telephone / Phone Sets and Features - SOU IT and Service Center Help Desk

External power for 8434D digital phones

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Identifying the type of external power being used

There are 3 types of power injection used with these digital phones:

  • Power injected at the wall jack through a splitter
  • Power injected under the desk through an inline injection box
  • Power injected through the phone line (from the electrical closet)


External power using a splitter62951100ZGXGWSJASXMGWGX0-Power_Splitter.jpg


This type of power injection uses both a power brick plugged in to either a wall outlet or to a surge suppressor.  This power injection method is easily identifiable by the "y" splitter plugged into the wall jack (as seen on the right).

The bottom portion of the splitter runs to the power brick similar to the one seen on the left.  This jack is smaller than that the other.

The top portion of the splitter runs to the phone.  This is the larger of the two jacks on the splitter.















External power using an inline injector

This type of power injection uses an inline power injection unit similar to the one see on the right.  This injector has two identical jacks located on the front.  These jacks will be labeled as the whether they are to be run the the "Phone" or to the "Line".  There is also a power cable plugged into the back of the power injection unit.



External Power from the wiring closet

If there is no visible power injection unit, the power may have been injected through the phone line.


Troubleshooting power issues

Loss of Caller-ID

The loss of Caller-ID is fairly common with those phones, but luckily there usually is a simply fix.  These phones require external power for the Caller-ID display.  The phone will still function without external power, but the Caller-ID information will not appear on the screen.

  1. Identify the type of power injection used (as described above)
    • If the power is injected from the wiring closet skip to step 3
  2. Ensure that all of the line cords are plugged in properly (as described above)
  3. Unplug the phone line from the back of the phone for a couple of seconds and plug it back in. 
  4. If none of these work, or there is no power brick, let us know and we will have to troubleshoot the issue further.
  • To test whether the screen is working, you can simply pick up the handset you should see an "a=" appear on the screen.

Resetting the speakerphone

Sometimes after a power outage the phone will require you to reset the speakerphone.  This can usually be accomplished in two ways

  • If the digital display prompts you to reset the speaker, you can simply press the button below the "Begin" label.
  • If there isn't a prompt on the digital display you can press the "Shift" button along with the "Ring" button.

Turning on/off the time

To turn on the time feature (which can sometimes be lost after a power outage)

  1. Press the "Menu" button
  2. Press the button below the "TMDay" label
  3. Wait to the date and time to disappear
  4. Press the "Exit" button

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