Problem with Keypad on NX-8E


I am really "green" in this business, but I decided to go on my own and I've bought
CADDX NX-8E kit with the following equipment:
  • LCD Keypad (NX-148E-RF)
  • Motion Sensor (PI6000)
  • Door/Window Sensor (60-670-95R)
So after connecting all of them, the problem I am having is a keypad: it does not respond at all, however if I switched POS with COM it starts flashing and reports "Control Power Trouble".

Does somebody know why Keypad might not work?

And another question if there is a minimum system requirements?

Thank you
Might want to try this.

First make sure nothing is shorting out inside the metal box. Wrap the leads that go to the battery in electrical tape so they don't short to anything.

Unplug everything from the NX8E board. Now just install the wall wart power leads (as shown on the schematic) and tie an EOL resistor between the eight zones and their commons (so it looks like the zones are always closed).

Then bring the LCD keypad to the NX8E box and, using a short piece of four conductor wire, wire the keypad to the NX8E exactly as shown on the schematic diagram inside the metal box.

Power the system and hopefully you will see something like "siren fault".

I'm thinking you have something shorting out your on-board 12 volt supply.
Thank you for reply,
I have made what you suggested, but Keypad still does not work.

I have attached a picture of the control panel and LCD Keypad:

(I am using 4-conductor 22 gauge wire)
a red wire - DATA
a white wire - POS
a green wire - COM
a black one - not connected

As you may see all 8 zones are connected with 3.3K EOL to COMMON.

May be my keypad is broken.



  • NX8E_KEYPAD.jpg
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Measure the voltage at the keypad Positive and Negative wires to make sure you have voltage and proper polarity there.

You should not be able to swap the power leads and the keypad start working. Check polarity on your leads.
Yea, this doesn't look good. As Spanky suggested take a meter and set it to DC volts and see if you have twelve volts between KP POS and KP COM.

Also see if you have twelve volts between AUX PWR and COMMON.

Then set your meter on AC Volts and measure the voltage across the "AC" terminals.
Say, you are using the large "wall wart" supplied with the kit correct? There are two screws on it. You just connected a pair of wired to those screws and then to the "AC" terminals on the NX8E board correct?

Is the battery disconnected and the leads to it (from the board) wrapped in electrical tape?

Stupid question, but is the AC outlet OK?

Just for grins, disconnect the AC leads (remove the wall wart power from the board), connect the battery leads to the battery and see what happens.

Is their a fuse on the board? (I can't remember).
I measured all what you asked:

1) AUX PWR - COM: 13.8V
2)AC - AC: ~17.9V
3) And now something interesting for KP POS - KP COM:
A) When a keypad is disconnected it has the same volatage as AUX PWR: 13.8V
:) With connected keypad: KP POS - KP COM have only 0.8V
Addition to my previous e-mail:
When keypad is being connected there is 7v between KP DATA and KP COM.

And I don't see any fuseon the board.
It may have a PTC fuse that goes to high resistance when shorted. Disconnect power for a few minutes. It will have to cool down to pass current again. It would read a good voltage until you try to draw current from a connected keypad.
Can you tell what LEDs should flash?

On mine board only LED2 next to NetwokX box is blinking, and in the upper right corner LED3 and LED1 don't, is it okay?

When a keypad is disconnected it has the same volatage as AUX PWR: 13.8V
With connected keypad: KP POS - KP COM have only 0.8V

Sounds like the keypad is loading down your board. Did you purchase this locally?
They have a forum HERE for Caddx support also.

I think if the test Spanky suggested didn't work you may have a problem with that keypad. Also, those terminals are a little tricky (on the keypad) so you may want to recheck those connections. Did you use solid wire? If not, make sure no wire strands are touching another adjacent cable.