Bose Lifestyle 12 Service Manual

The Bose Lifestyle 12 is a premium home theater system featuring a media center, Acoustimass module, and cube speaker arrays. This service manual provides detailed technical information for authorized service personnel, including system overview, specifications, disassembly procedures, troubleshooting, parts lists, and schematics. Below are key sections covering safety, system components, installation guidelines, diagnostics, and repair instructions.

1. System Overview 2. Safety Precautions 3. Technical Specifications 4. Component Identification 5. Installation Guidelines 6. Disassembly Procedures 7. Diagnostic Tests 8. Troubleshooting Flowcharts 9. Parts List & Replacements 10. Schematics & Diagrams 11. Firmware & Calibration

System Overview

Key components: Lifestyle 12 Media Center (Model SA-3), Acoustimass Module (Model AM-5), Jewel Cube Speakers (x5), Universal Remote Control, IR Emitter, Power Cords, and Connection Cables.

Component	Description
Media Center (SA-3)	Main control unit with amplifier, tuner, and input/output ports
Acoustimass Module (AM-5)	Bass module for low-frequency reproduction
Jewel Cube Speakers	Five satellite speakers for surround sound
Universal Remote	Controls system functions and compatible devices
IR Emitter	For remote control signal transmission
Power Cords	AC power connections for components
Connection Cables	Speaker wires and audio/video interconnects
ADAPTiQ Headset	For room calibration (if included)
Setup Microphone	For automatic system calibration
Wall Mounts	Optional mounting hardware for speakers

Safety Precautions

Before servicing, review all safety warnings and procedures.

Disconnect AC power before opening any enclosure.
Use appropriate tools and ESD protection when handling circuit boards.
Verify replacement parts meet original specifications.
Reassemble all components securely before applying power.

WARNING! High voltages are present inside the media center and Acoustimass module. Only qualified personnel should perform internal service.

Technical Specifications

Media Center Power: 120V AC, 60Hz, 180W max.
Amplifier Output: 50W per channel (x5), 8 ohms.
Frequency Response: 35Hz - 20kHz (±3dB).
Inputs: Composite Video (x3), S-Video (x3), Analog Audio (x3), Digital Optical (x2), Coaxial Digital (x1).
Outputs: Composite Video Monitor, Subwoofer, Speaker Terminals.
Tuner: AM/FM with 30 presets.
Dimensions (Media Center): 16.5" W x 3.5" H x 12.5" D.
Weight: Media Center: 12 lbs; Acoustimass Module: 25 lbs.
Operating Temperature: 41°F to 95°F (5°C to 35°C).

Component Identification

Media Center Front Panel: POWER, INPUT SELECT, VOLUME, MUTE, DISPLAY. Rear Panel: Speaker terminals (Front L/R, Center, Surround L/R), Subwoofer output, Audio/Video inputs, Digital inputs, Antenna terminals, AC inlet.

Acoustimass Module: Input terminals, Phase switch, Level control, AC inlet. Jewel Cube Speakers: Positive/Negative terminals. Remote Control: POWER, NUMERIC, VOLUME, MUTE, MENU, NAVIGATION, TRANSPORT CONTROLS.

Internal Boards (Media Center): Main board, Power supply board, Tuner board, Display board. Connectors: J1 (Power), J2 (Speaker outputs), J3 (Front panel), J4 (Tuner).

Installation Guidelines

Speaker Placement: Front L/R: 6-15 ft apart; Center: above/below display; Surround L/R: beside/behind seating. Acoustimass Module: Corner placement recommended.

Connect speakers to media center terminals (observe polarity).
Connect subwoofer cable from media center to Acoustimass module.
Connect audio/video sources to appropriate inputs.
Connect antenna to AM/FM terminals.
Plug media center and Acoustimass module into AC outlets.
Run ADAPTiQ calibration with setup microphone.

Tip: Ensure all connections are secure before powering on.

Disassembly Procedures

Media Center Disassembly:

Remove four rubber feet and Phillips screws from bottom.
Slide top cover rearward and lift off.
Disconnect internal ribbon cables (note orientation).
Remove screws securing main board and power supply.
Lift boards carefully to access components.

Acoustimass Module Disassembly:

Remove grille cloth (if applicable).
Remove screws around driver baffle.
Separate cabinet halves to access internal components.

WARNING! Document cable positions and screw locations during disassembly.

Diagnostic Tests

Power Supply Test: Check DC voltages at test points TP1 (+12V), TP2 (+5V), TP3 (+3.3V). Amplifier Test: Inject 1kHz signal at input; verify output at speaker terminals. Tuner Test: Check RF signal strength and demodulation. Display Test: Verify backlight and segment operation.

Troubleshooting Flowcharts

Symptom	Possible Cause	Corrective Action
No power	AC cord, fuse, power supply	Check AC outlet; test fuse F1 (5A); verify power supply voltages.
No audio output	Input selection, mute, amplifier	Verify input source; check mute status; test amplifier IC (U201).
Distorted sound	Speaker wiring, amplifier	Check speaker connections for shorts; test amplifier output stages.
No display	Display board, connections	Check ribbon cable J3; test display board voltages; replace display if needed.
Remote not working	Batteries, IR sensor	Replace batteries; test IR sensor at Q101; check remote with IR tester.
No bass output	Subwoofer cable, module	Verify cable connection; test Acoustimass module input; check phase switch.

Parts List & Replacements

Fuse: 5A, 250V, slow-blow (P/N 123456)
Power Transformer: 120V/24V (P/N 234567)
Main Capacitor: 4700µF, 35V (P/N 345678)
Amplifier IC: STK405-070 (P/N 456789)
Display Module: VFD, 16-segment (P/N 567890)
Jewel Cube Speaker: Complete assembly (P/N 678901)
Acoustimass Driver: 5.25" woofer (P/N 789012)
Remote Control: Complete (P/N 890123)
Power Cord: 3-prong, 6 ft (P/N 901234)
Ribbon Cable: 20-pin, 6" (P/N 012345)

Schematics & Diagrams

Block Diagram: Signal flow from inputs to outputs. Power Supply Schematic: AC input to DC outputs. Amplifier Schematic: Input stage to speaker outputs. Display Schematic: Driver circuit and connections. Layout Diagrams: Component placement on all boards.

Note: Refer to separate schematic sheets for detailed circuit diagrams.

Firmware & Calibration

Firmware Version: Check via menu > System > Information. Update Procedure: Requires service tool (Bose updater) and serial cable. Calibration: Run ADAPTiQ calibration after any speaker replacement or relocation. Reset Procedures: Factory reset clears all settings (menu > System > Reset).

Service Support: For technical assistance, contact Bose Professional Support at 1-800-999-2673 or visit pro.bose.com.