Bose AV28 Media Center Service Manual

The Bose AV28 Media Center is a high-performance audio/video control system designed for home theater integration. It features multi-zone audio control, video switching, AM/FM tuner, compatibility with various audio sources (CD, DVD, streaming), system remote control, RS-232 and IR control ports, and advanced audio processing. Below are key sections for safety, technical specifications, installation, configuration, operation, diagnostics, and service procedures.

System Overview

Key components: Main Control Unit, System Remote Control, Power Supply, IR Emitters, RS-232 Control Cable, Antenna Connectors.

Technical Specifications

• Audio Amplification: Multi-zone, up to 60 watts per channel.
• Tuner: AM/FM with 30 station presets.
• Audio Inputs: 6 analog stereo, 3 digital (2 optical, 1 coaxial).
• Video Inputs: 4 composite, 3 S-Video, 2 component.
• Audio Outputs: 3 zones (Main Zone + 2 additional).
• Video Outputs: Main Zone and Zone 2 composite/S-Video.
• Control: RS-232, IR input/output, 12V trigger.
• Power Requirements: 120V AC, 60Hz, 250W max.
• Operating Temperature: 41°F to 95°F (5°C to 35°C).

Installation & Wiring

Unpack and inspect all components. Choose a well-ventilated location.

1. Power Connection: Connect the supplied power cord last. Ensure unit is off.
2. Antenna Connection: Connect AM loop and FM wire antennas to respective terminals.
3. Source Connections: Connect audio/video sources to appropriate inputs (e.g., DVD to Input 1).
4. Output Connections: Connect speaker wires to correct terminals for each zone. Connect video outputs to displays.
5. Control Wiring: Connect IR emitters to source devices. Connect RS-232 cable if using external control.

WARNING! Disconnect AC power before making any connections. Ensure proper ventilation to prevent overheating.

Initial Configuration

Power on the unit; the system will enter setup mode.

1. Source Assignment: Use the on-screen menu to name and assign each input (e.g., "Cable Box", "Blu-ray").
2. Zone Setup: Define which sources are available in Zone 2 and Zone 3.
3. Tuner Setup: Auto-scan for AM/FM stations and assign presets.
4. Remote Setup: Program the system remote to control connected sources.
5. Audio Calibration: Run the built-in speaker setup for level and balance.

CAUTION! Follow on-screen prompts carefully. Incorrect settings may affect system performance.

Control & Interface

Access the main menu via the front panel MENU button or remote. Front Panel: POWER, MENU, ZONE SELECT, VOLUME knob, INPUT SELECT.

Remote Control: POWER, ZONE buttons, Numeric keypad, VOLUME, MUTE, INPUT SELECT, TRANSPORT controls (Play, Stop, etc.), MENU, GUIDE, INFO.

On-Screen Menu: SOURCE, ZONE, SETTINGS, TUNER, FAVORITES. Settings: Audio (Bass, Treble, Balance, Loudness), Video (Output resolution, aspect ratio), System (Language, default volume, auto-off).

Source Connection Guide

Connect sources to appropriate inputs for optimal performance.

1. Digital Audio Source (e.g., CD player): Use optical or coaxial digital input for best quality.
2. Analog Audio Source (e.g., Turntable with preamp): Use analog stereo RCA inputs.
3. Video Source (e.g., Cable Box): Use highest quality connection available (Component > S-Video > Composite).
4. Assign IR Emitter: Place the IR emitter over the source device's IR sensor for remote control pass-through.

Tip: Label all cables during installation for easier service and troubleshooting.

Multi-Zone Setup

The system supports independent audio in up to three zones.

1. Define Zones: In SETTINGS > ZONE CONFIGURATION, enable Zone 2 and Zone 3.
2. Source Selection: Specify which audio sources are available in each secondary zone.
3. Volume Control: Set maximum volume limits per zone for safety.
4. Output Type: Select between amplified speaker output or line-level output for each zone.

Note: Video is typically only available in the Main Zone and Zone 2 (composite/S-Video).

Diagnostics & Testing

Access the Service Menu by pressing and holding MENU and ZONE 2 on the front panel for 5 seconds.

• System Test: Runs automated checks on audio paths, video switching, and control circuits.
• Signal Meter: Tests tuner signal strength for AM and FM.
• IR Test: Verifies IR input and output functionality.
• Temperature Monitor: Displays internal operating temperature.
• Error Log: View stored error codes for past system faults.

WARNING! The Service Menu is for qualified technicians. Do not change advanced settings without proper knowledge.

Firmware Update

Firmware can be updated via RS-232 connection or from a CD.

1. Via RS-232: Connect a PC running the Bose updater software to the RS-232 port. Follow on-screen instructions.
2. Via Audio CD: Load the update CD into a connected CD player assigned to an analog input. The system will detect and install.
3. Verification: After update, navigate to SETTINGS > SYSTEM INFO to confirm new firmware version.

CAUTION! Do not interrupt power during a firmware update. This can render the unit inoperable.

Regulatory & Compliance

FCC Part 15: Class B digital device. Complies with Canadian ICES-003. This product conforms to all applicable U.S. and international regulations. Copyright © Bose Corporation. All trademarks are the property of Bose Corporation. For technical support and service, visit www.bose.com/support or contact Bose Customer Service.

Troubleshooting & Service

Factory Reset: In Service Menu, select "Restore Factory Defaults". This will erase all custom settings.

Service Contact: For service, contact authorized Bose service centers only. Do not open the unit as it contains no user-serviceable parts.