Bose 3-2-1 Service Manual

1
Preliminary
CONTENTS
Accessories ....................................................................................................................................... 2
Safety Information ............................................................................................................................ 3
Electrostatic Discharge Sensitive (ESDS) Device Handling ......................................................... 3
Warranty...

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Preliminary
CAUTION: The Bose® 3-2-1 Home Entertainment System contains
no user-serviceable parts. To prevent warranty infractions,
refer servicing to warranty service stations or factory service.
       PROPRIETARY INFORMAT ION
THIS  DOCUMENT  CONTAINS  PROPRIETARY  INFORMATION  OF
BOSE  CORPORATION  WHICH  IS  BEING  FURNISHED  ONLY  FOR
THE  PURPOSE    OF  SERVICING THE  IDENTIFIED  BOSE  PRODUCT
BY  AN  AUTHORIZED  BOSE  SERVICE  CENTER  OR  OWNER  OF
THE  BOSE  PRODUCT,  AND  SHALL  NOT  BE...

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Preliminary
SAFETY  INFORMATION
1. Parts that have special safety characteristics are identified by the          symbol on schematics
or by special notes on the parts list. Use only replacement parts that have critical characteristics
recommended by the manufacturer.
2. Make leakage current or resistance measurements to determine that exposed parts are
acceptably insulated from the supply circuit before returning the unit to the customer. Refer to
Paragraph 84 of UL1270. Use the following checks to...

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Preliminary
SPECIFICATIONS
System Specifications:
Power  Rating:USA/Canada: 120VAC, 50/60 Hz, 300W
Console Inputs:AUX, Video 1, Video 2
Console  Outputs:1 Audio Output (AUX), 1 Composite Video
Output and 1 S-Video Output
External Antennas:FM, 75 Ohm, 3.5 mm mono connector
AM Loop, 2.5 mm mono connector
Maximum Ambient Temperature:40 degrees C
Maximum Product Power Dissipation:47 Watts
Low Frequency Cut-off (-3dB nearfield):Array Cube: 200 Hz
Bass Module: 50 Hz
Maximum SPL:105 dB SPL acoustic output at...

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Preliminary
SPECIFICATIONS
Console Specifications (continued):
Compression Formats Supported for
sources connected to the digital inputs:AAC,  AC-3,  DTS,  MPEG-2
CD/DVD  Drive  Performance:
Interface:ATAPI
Data Transfer  Rate:Sustained Mode (DVD): 2704-6536 kbs
Sustained Mode (CD-ROM mode 1) 2069-4800
max  kbs
Access Time:DVD-ROM  CD-ROM  (32x)
Average Random Seek 105ms-95ms
Average  Random  Access  135ms-95ms
Average  Full  Stroke  Access  230ms-160ms
CD Playability Requirements:
Physical...

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Preliminary
Console Specifications (continued):
DC  Offset:< 50 mVdc, all channels
Channel Balance:+/- 1.5 dB for all volume settings
Channel Separation:> 40 dB @ 1 kHz, > 30 dB @ 10 kHz,
stereo mode
Analog Input Characteristics:
Maximum source signal for ADC full scale:2 Vrms
Minimum source signal for ADC full scale:200 mVrms
Input Impedance:100k Ohms nominal +/- 10%
Input  Coupling:AC coupled to remove source DC offset
Analog Output (Aux) Characteristics:
Output level from 0 dBFS:1 Vrms at less than...

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Preliminary
SPECIFICATIONS
Console Specifications (continued):
FM Tuner Performance (per IHF-T-200):
Channel Spacing:200  kHz
Band Limits:87.5 MHz - 107.9 MHz
De-emphasis:75 usec
50 dB Quieting Sensitivity:
Mono:13 dBf nominal / 17 dBf limit
Stereo:38 dBf / limit 42 dBf
Signal to Noise Ratio @ 65 dBf:74 / limit 69 dB mono, 70 / limit 65 dB stereo
Harmonic Distortion @ 65 dBf:Mono 0.3% / limit 0.6%, stereo 0.4% / limit 0.8%
Capture Ratio @ 45 dBf:2.0 dB nominal / limit 3.0 dB
AM Rejection @ 45 dBf:60 dB...

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Preliminary
INPUTSVIDEO ANTENNA ANALOG
AUDIODIGITAL
AUDIO
COMPOSITE
S-VIDEO
AM
FM
VIDEO 1
VIDEO 2
AUX INPUT
VIDEO 1
VIDEO 2
AUX INPUT
OUTPUTS
VIDEO TWIDDLER BASS 
MODULEANALOG
AUDIO
COMPOSITE
S-VIDEO
LC
LS
RC
RS
BASS
AUX OUT L
AUX OUT R POWER
AMP
DAC DSP CODEC
DVD-ROMDVD
PROCESSORVIDEO 
ENCODERAUDIO/
VIDEO
MUX
TUNER
DIGITAL
AUDIO
RECEIVER
Figure 1. 3-2-1 Console Block Diagram 

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Preliminary

	
	 



Bass Module Procedures
Refer to Figure x for the following proce-
dures.
1. Rear Enclosure Removal
1.1 Place the bass module on its side.
Using a Phillips-head screwdriver, remove
the four screws (9) that secure the rear
enclosure (8) to the bass module.
1.2 Slide the rear enclosure off of the bass
module.
2. Rear Enclosure Replacement
2.1 Align the rear enclosure (9) with the bass
module so that the bass module PCB/
heatsink assembly (10) connecters are...

10
Preliminary
Console Procedures
Note: Refer to Figure x for the following
procedures.
1. Top Cover Removal
1.1 Place the console on the bench with the
front facing toward you. On the rear of the
console and using finger pressure only,
press inward in the center of the rear panel
just below the edge of the top cover (2).
When you have pressed the rear panel in
approximately 1/4", lift upward on the top
cover and release the pressure on the rear
panel of the console. The finger in the center
of the...