Keypad and Display Assemblies

Owned by Brian Ross
Last updated: 2024/09/27
3 min read

Scope

This document describes all variants of the Comb Keypad and Display assemblies. The document lists the changes between the versions and the Engineering Change Notices (ECN).

PCB Version: KPBL101-F

Release Date: 2018

Back Image

Front Image

Features:

  1. Keypad directly mounted onto Keypad/LCD PCB. 

  2. Fixed missing track between amplifier and output capacitor on KP101-E PCB.

  3. Removed ESD diodes from keypad as these would cause the I/O devices to blow on the main Intercom PCB.

  4. Backlight keypad.

  5. Onboard microphone.

  6. Pluggable LCD module.

Applicable ECN's

Remove the following diodes from the PCB:
D17, D20, D21, D24, D25, D28, D29, D32, D33, D36, D37, D40,
D41, D44, D45, D48, D49, D52, D53, D56, D57, D60, D61, D64

Check R10 for placement.

If not fitted, fit a 1M ohm 1206 SMD resistor.

Remove the capacitor C7.

Place the 0805 100R resistor.

Add a 10mm x 7mm acoustic sponge

Pink_Sponge.jpg

Place the acoustic sponge plug into the standard microphone rubber ring.

Pink_sponge.png

PCB Version: KPBL101-E

Release Date: 2018

Back Image

Front Image

Features:

  1. Increased the size of the contrast variable resistor.

  2. Keypad directly mounted onto Keypad/LCD PCB. 

  3. Added ESD diodes to protect Intercom from static discharge.

  4. Backlight keypad.

  5. Onboard microphone.

  6. Pluggable LCD module.

Applicable ECN's


Description

Diagram

Add a wire bridge between Pin 1 of U2 and R9

Remove the following diodes from the PCB:

D17, D20, D21, D24, D25, D28, D29, D32, D33, D36, D37, D40,
D41,D44, D45, D48, D49, D52, D53, D56, D57, D60, D61, D64

Check R10 for placement.

If not fitted, fit a 10 ohm 1206 SMD resistor.

Remove the capacitor C7.

Place the 0805 resistor.

Add a 10mm x 7mm acoustic sponge

Pink_Sponge.jpg

Place the acoustic sponge plug into the standard microphone rubber ring.


PCB Version: KPBL101-D
Release Date: 2016

Back Image

Front Image

Features:

  1. SMD contrast control.

  2. Keypad directly mounted onto Keypad/LCD PCB. 

  3. Backlight keypad.

  4. Onboard microphone.

  5. Pluggable LCD module.

Applicable ECN's


Description

Diagram

Add a 10mm x 7mm acoustic sponge

Pink_Sponge.jpg

Place the acoustic sponge plug into the standard microphone rubber ring.

PCB Version: KPBL101-C
Release Date: 2011

Back Image

Front Image

Features:

  1. Standard contrast control.

  2. Keypad PCB separate from Keypad/LCD PCB. 

  3. Backlight keypad.

  4. First iteration of the onboard microphone.

Applicable ECN's


Add a 10mm x 7mm acoustic sponge

Pink_Sponge.jpg

Place the acoustic sponge plug into the standard microphone rubber ring.

PCB Version: KP202
Release Date: 2008

Back Image

Front Image

Features:

  1. Simple PCB to interface ribbon connector to the keypad and LCD.

  2. Standard contrast control.

  3. No backlight keypad.

  4. No onboard microphone.

Applicable ECN



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http://www.comb-communications.com