Cisco 3842 Phone Manual

The Cisco 3842 is a business IP phone designed for high-volume call environments, featuring a high-resolution display, multiple programmable line keys, support for Power over Ethernet (PoE), integrated Gigabit Ethernet switch, headset and handset ports, speakerphone, and advanced call management features. It operates on Cisco Unified Communications Manager (CUCM) and supports SIP protocols. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Devices 7. Advanced Call Features 8. Accessibility Features 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: High-resolution LCD display, Programmable line keys, Handset, Speakerphone, Headset jack, Ethernet ports, Navigation cluster.

Feature	Description
Display	High-resolution backlit LCD for call information and menus
Line Keys	Multiple programmable keys for lines, speed dials, and features
Handset	Full-duplex speakerphone with wideband audio support
Headset Port	3.5mm jack for wired headset connectivity
Ethernet Ports	Two 10/100/1000 Mbps ports with integrated switch
Power	802.3af PoE or optional AC power adapter
Navigation Cluster	Directional pad for menu navigation and selection
Volume Control	Dedicated buttons for handset, headset, and speaker volume
MUTE	Button to mute microphone during calls
HOLD	Button to place active calls on hold

Installation

Unpack and inspect contents. Place on stable surface.

Connect to network: Use Ethernet cable to connect LAN port to network switch.
Connect PC (optional): Use PC port to connect computer for pass-through networking.
Connect handset: Plug coiled handset cord into handset jack.
Connect headset (optional): Plug into 3.5mm headset jack.
Apply power: Use PoE from switch or connect AC power adapter.

WARNING! Use only approved power sources. Ensure network cables are securely connected.

First-Time Setup

Phone will boot and register with Cisco Unified Communications Manager.

Network registration: Phone obtains IP address via DHCP and contacts CUCM.
Configure extension: Administrator assigns directory number and features.
User preferences: Use phone settings menu to set language, ringtone, display contrast.
Program keys: Administrator or user can assign functions to line keys.
Test call: Place test call to verify audio quality and connectivity.

CAUTION! Do not disconnect during firmware upgrade. Ensure proper ventilation.

Specifications

Display: High-resolution grayscale or color LCD.
Network: 10/100/1000 Mbps Ethernet with PoE (802.3af).
Audio: Wideband audio support, HD voice capable.
Protocols: SIP and SCCP support.
Power: 802.3af PoE or 48V DC power adapter.
Physical: Desk mountable, adjustable footstand.
Environmental: Operating temperature 32°F to 104°F (0°C to 40°C).
Compliance: FCC Part 15, UL, CE.

Controls and Settings

Access settings via phone menu button. Front buttons: MUTE, HOLD, VOLUME, NAVIGATION, LINE KEYS.

Menu Navigation: Use directional pad to navigate settings menus.

Basic Settings: Ringtone selection, display contrast, date/time format. Network: View IP address, subnet mask, gateway. Call Features: Call forward, do not disturb, speed dials. Audio: Adjust handset, headset, speaker volume levels. Security: Phone lock, authentication settings (configured via CUCM).

Connecting Devices

Network: Ethernet cable to switch. PC: Connect to PC port for network pass-through. Headset: 3.5mm jack.

Turn off phone before connecting devices (if using AC adapter).
Match cables to correct ports (Ethernet to network, handset to handset jack).
Verify connections are secure.

Tip: Use quality CAT5e or higher Ethernet cables for best performance.

Advanced Call Features

Supports multiple lines, call forwarding, conferencing, transfer.

Make call: Lift handset or press speaker button, dial number.
Answer call: Press line key, answer button, or lift handset.
Hold: Press HOLD button to place call on hold.
Transfer: During call, press TRANSFER, dial target, press TRANSFER again.
Conference: During call, press CONFERENCE, dial participant, press CONFERENCE to join.
Forward: Access call forwarding menu to set forward-to number.
Speed dial: Program speed dials on line keys for one-touch dialing.
Call history: Press DIRECTORY to view missed, received, placed calls.

WARNING! Emergency calls may require direct dialing without prefixes.

Accessibility Features

Hearing Aid Compatible (HAC): Handset meets HAC standards. Visual Alerts: Flashing line keys for incoming calls. Audio Adjustments: Independent volume controls for handset, headset, ringer, speaker. High-Contrast Display: Options for improved visibility.

Care & Cleaning

Disconnect power before cleaning. Use soft, dry cloth; avoid liquids or abrasive cleaners.

CAUTION! Do not use aerosol sprays; keep away from excessive heat and moisture.

Regulatory Information

FCC Part 15: Class A digital device; complies with limits for business environments. Copyright © Cisco Systems, Inc. All rights reserved. For technical support, visit www.cisco.com or contact Cisco Technical Assistance Center. This product may be covered by one or more patents.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No display/power	Power source	Check PoE switch or AC adapter; verify cable connections.
No network connectivity	Cable/DHCP	Check Ethernet cable; verify switch port; confirm DHCP server.
No audio	Volume/mute	Adjust volume; check mute status; verify handset connection.
Cannot register	Configuration	Verify CUCM configuration; check network connectivity to CUCM.
Poor call quality	Network/QoS	Check network for congestion; verify QoS settings on switch.

Reset: Press and hold # key during boot for factory reset (erases configuration).

Service: Contact Cisco TAC or authorized service provider.