Bose Lifestyle 25 Repair Manual

The Bose Lifestyle 25 is a premium home entertainment system featuring a media center, Acoustimass module, and cube speakers. This manual provides detailed repair, troubleshooting, and maintenance procedures for qualified technicians. It covers system overview, disassembly instructions, component testing, common fault diagnosis, and reassembly guidelines. Use this manual in conjunction with proper tools and safety precautions.

1. System Overview & Safety 2. Tools & Test Equipment 3. Disassembly Procedures 4. Component Specifications 5. Circuit Board Diagnostics 6. Acoustimass Module Repair 7. Cube Speaker Servicing 8. Remote & Control Issues 9. Software & Reset Procedures 10. Reassembly & Testing 11. Troubleshooting Flowcharts

System Overview & Safety

Key components: Media Center (Model SA-3), Acoustimass Bass Module (Model AM-3), Jewel Cube Speakers (left/right/center/surround), Remote Control (RC-1), power cords, and connection cables.

Component	Function
Media Center (SA-3)	Main control unit with amplifier, tuner, and input/output connections
Acoustimass Module (AM-3)	Powered bass unit for low-frequency reproduction
Jewel Cube Speakers	Satellite speakers for mid/high frequencies
Remote Control (RC-1)	Infrared remote for system operation
Power Cords	AC power supply for Media Center and Bass Module
Connection Cables	Proprietary cables for speaker and control connections

WARNING! Disconnect all power before servicing. High voltages are present inside components. Use anti-static precautions.

Tools & Test Equipment

Required for repair: Phillips screwdrivers (#0, #1), Torx drivers (T8, T10), multimeter, oscilloscope, soldering iron (ESD-safe), desoldering tools, anti-static wrist strap, and Bose service software (if available).

Multimeter: For voltage, continuity, and resistance checks.
Oscilloscope: For signal tracing on audio circuits.
ESD Protection: Always use wrist strap when handling circuit boards.
Service Software: For system diagnostics and firmware updates.

CAUTION! Use correct tool sizes to avoid damaging fasteners. Label all cables during disassembly.

Disassembly Procedures

Media Center: Remove bottom screws, lift top cover. Acoustimass Module: Remove grille, then rear panel screws. Cube Speakers: Pry off front grille carefully.

Power off and unplug all components.
Media Center: Remove 6 Phillips screws from bottom, slide top cover forward.
Acoustimass Module: Remove 8 Torx screws from rear panel.
Cube Speakers: Insert flat tool at grille notch, gently pry outward.
Document screw locations and cable orientations.

WARNING! Bass module contains large capacitors; allow time to discharge before handling.

Component Specifications

Media Center Power: 120V AC, 60Hz, 100W max.
Amplifier Output: 25 watts per channel (all channels driven).
Bass Module Power: Built-in 100W amplifier.
Speaker Impedance: 4-8 ohms (cube speakers).
Fuse Ratings: Media Center: T2A/250V; Bass Module: T3.15A/250V.
Operating Temperature: 41°F to 95°F (5°C to 35°C).
Dimensions: Media Center: 16.5" W × 3.6" H × 12.9" D.

Circuit Board Diagnostics

Main boards in Media Center: Power supply, amplifier, digital processing. Test points marked on boards.

Power Supply: Check +5V, +12V, -12V rails. Amplifier Section: Test output transistors for shorts. Digital Board: Verify clock signals and processor operation.

Common failures: Bulging capacitors on power supply, failed output transistors, cracked solder joints on connectors.

Acoustimass Module Repair

Contains amplifier plate and driver assembly. Common issues: No bass output, hum, protection mode.

Check fuse on amplifier plate.
Test output transistors (Q701-Q704).
Measure driver coil resistance (should be 4-6 ohms).
Inspect capacitor C801 for bulging/leaking.
Test thermal protection circuit.

Tip: Use isolation transformer when testing amplifier live.

Cube Speaker Servicing

Jewel Cube speakers use 2.5" full-range drivers. Issues: No sound, distorted audio, rattling.

Remove grille (pry carefully at notches).
Check driver continuity (should be 4-8 ohms).
Inspect cone for damage or separation.
Test crossover components if present.
Verify cable connections at terminal.

WARNING! Driver diaphragms are fragile; avoid pressure on cone.

Remote & Control Issues

RC-1 remote: Check batteries, IR LED, keypad contacts. Media Center front panel: Test buttons, display.

Software & Reset Procedures

System reset: Unplug Media Center for 2 minutes, then reconnect. Factory reset: Press and hold "1" and "4" on remote while powering on.

CAUTION! Factory reset erases all settings and presets.

Reassembly & Testing

Reverse disassembly steps. Ensure all connectors are secure. Test before final assembly.

Reconnect all internal cables.
Replace covers and fasteners.
Power on and test all functions.
Verify audio on all channels.
Test remote operation.

Tip: Perform audio test with known good source material.

Troubleshooting Flowcharts

Symptom	Possible Cause	Corrective Action
No power (Media Center)	Fuse, power supply	Check AC cord; test fuse F101; measure DC outputs.
No audio (all channels)	Main amplifier, mute circuit	Test amplifier IC501; check mute transistor Q502.
One channel dead	Output transistor, speaker cable	Test output pair for that channel; verify cable continuity.
Bass module not working	Fuse, amplifier plate	Check fuse F701; test amplifier output; verify signal input.
Remote not working	Batteries, IR sensor	Replace batteries; test IR LED with camera; check sensor on Media Center.

Service Contacts: Bose Corporation Service Division: 1-800-999-2673; www.bose.com/support