Bose 3-2-1 Service Manual

							1
Preliminary
CONTENTS
Accessories ....................................................................................................................................... 2
Safety Information ............................................................................................................................ 3
Electrostatic Discharge Sensitive (ESDS) Device Handling ......................................................... 3
Warranty ............................................................................................................................................. 3
Specifications ................................................................................................................................ 4-7
Figure 1. 3-2-1 Console Block Diagram ............................................................................................8
Disassembly/Assembly Procedures ......................................................................................... 9-13
Test Procedures ........................................................................................................................ 14-23
Figure 2. Laser voltage test points ..................................................................................................16
Figure 3. Laser current rating label .................................................................................................16
Figure 4. AM Loop Antenna Test Setup ...........................................................................................17
Part List Notes ................................................................................................................................. 24
Main Part List, Console Assembly (see Figure 5)........................................................................ 24
Figure 5. Console Exploded View ...................................................................................................25
Main Part List, Bass Module Assembly (see Figure 6)................................................................ 26
Figure 6. Bass Module Assembly Exploded View ...........................................................................26
Main Part List, Bass Module PCB Assembly (see Figure 7)........................................................ 27
Figure 7. Bass Module PCB Assembly Exploded View ..................................................................27
Electrical Part Lists ................................................................................................................... 28-46
Console Main PCB Assembly .................................................................................................. 28-43
Console LCD Display PCB Assembly ..................................................................................... 43-44
Bass Module PCB Assembly ................................................................................................... 45-46
Packaging Part List, 3-2-1 Home Theater System System (see Figure 8).................................. 46
Figure 8. 3-2-1 Home Theater System Packaging View .................................................................47
Accessory Kit Part List, 3-2-1 Home Theater System Accessory Kit (see Figure 9)................ 48
Figure 9. Accessory Kit Exploded View ..........................................................................................48
Integrated Circuit Diagrams ..................................................................................................... 49-62
Appendix .................................................................................................................................... 63-85
Figure 10. 3-2-1 Console Test Setup Diagram ................................................................................63
Figure 11. 3-2-1 Bass Module Test Setup Diagram .........................................................................64
Figure 12. 3-2-1 Speaker Array Wiring Diagram .............................................................................64
Figure 13. DVD Mechanism Rear Panel .........................................................................................65
Figure 14. Bass Module Test Cable Wiring ......................................................................................66
Figure 15. Tap Interface cable wiring diagram .................................................................................67
Bass Module Troubleshooting Information .................................................................................. 85
Parental Control Information ......................................................................................................... 85
Table 1. 3-2-1 Console DVD Parental Control Rating Codes ..........................................................85
Table 2. Region Codes and Covered Areas ....................................................................................85
Figure 17. LCD Display PCB Component and Bottom Etch Rev. 00 Diagram ................................86
Figure 16. LCD Display PCB Component and Topside Etch Rev. 00 Diagram ...............................86
Figure 19. LCD Display PCB Component and Bottom Etch Rev. 01 Diagram ................................87
Figure 18. LCD Display PCB Component and Topside Etch Rev. 01 Diagram ...............................87
Figure 20. Bass Amplifier PCB Rev. 00 Component and Etch Layout Diagram .............................88
Figure 21. Bass Amplifier PCB Rev. 01 Component and Etch Layout Diagram .............................89
Glossary of Terms ........................................................................................................................... 90 
						

							2
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  REPRODUCED  OR
USED  FOR  ANY  OTHER  PURPOSE.
Accessories
The Bose
® Model 3-2-1 home entertainment system shelf speakers are compatible with Bose
mounting accessories, including the UB-20 wall brackets, UFS-20 floor stands and UTS-20
table stands. 
						

							3
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 perform these measurements:
A. Leakage Current Hot Check-With the unit completely reassembled, plug the AC line cord
directly into a 120V AC outlet. (Do not use an isolation transformer during this test.) Use a
leakage current tester or a metering system that complies with American National Standards
Institute (ANSI) C101.1 "Leakage Current for Appliances" and Underwriters Laboratories (UL)
1492 (71). With the unit AC switch first in the ON position and then in OFF position, measure
from a known earth ground (metal waterpipe, conduit, etc.) to all exposed metal parts of the unit
(antennas, handle bracket, metal cabinet, screwheads, metallic overlays, control shafts, etc.),
especially any exposed metal parts that offer an electrical return path to the chassis. Any cur-
rent measured must not exceed 0.5 milliamp. Reverse the unit power cord plug in the outlet and
repeat test. ANY MEASUREMENTS NOT WITHIN THE LIMITS SPECIFIED HEREIN INDI-
CATE  A  POTENTIAL  SHOCK  HAZARD THAT  MUST  BE  ELIMINATED  BEFORE  RETURNING
THE  UNIT TO THE  CUSTOMER.
B. Insulation Resistance Test Cold Check-(1) Unplug the power supply and connect a jumper
wire between the two prongs of the plug. (2) Turn on the power switch of the unit. (3) Measure the
resistance with an ohmmeter between the jumpered AC plug and each exposed metallic cabinet
part on the unit. When the exposed metallic part has a return path to the chassis, the reading
should be between 1 and 5.2 Megohms. When there is no return path to the chassis, the reading
must be "infinite". If it is not within the limits specified, there is the possibility of a shock hazard,
and the unit must be repaired and rechecked before it is returned to the customer.
ELECTROSTATIC  DISCHARGE  SENSITIVE  (ESDS)
DEVICE HANDLING
This unit contains ESDS devices. We recommend the following precautions when repairing,
replacing or transporting ESDS devices:
• Perform work at an electrically grounded work station.
• Wear wrist straps that connect to the station or heel straps that connect to conductive
  floor mats.
• Avoid touching the leads or contacts of ESDS devices or PC boards even if properly
  grounded. Handle boards by the edges only.
• Transport or store ESDS devices in ESD protective bags, bins, or totes. Do not insert
  unprotected devices into materials such as plastic, polystyrene foam, clear plastic bags,
  bubble wrap or plastic trays.
The Bose® 3-2-1 Home Entertainment System is covered by a limited 1-year transferable warranty
WARRANTY 
						

							4
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 400 Hz at
1 meter
Weight:Packed System: 35.5 lb (16.1 kg)
Console: 7.0 lb (2.7 kg)
Bass Module: 26.5 lb (12.0 kg)
Arrays (each): 3.0 lb (1.4 kg)
IR Remote: 0.26 lb (0.1 kg)
Dimensions:Console: 9.8 x 12.8 x 3.9 inches
(250 mm x 326 mm x 99.5 mm)
Bass Module: 14 x 7.5 x 20.1 inches
(35.6 cm x 18.4 cm x 51.1 cm)
Bass Module internal volume:
1205 cubic inches (19.7 liters)
Arrays: 7.9 x 5.3 x 3.4 inches
( 200 mm x 134 mm x 86 mm)
IR Remote:
(65 mm x 204 mm x 30 mm)
Console Specifications:
Compression Formats Supported for
discs inserted into the DVD/CD drive:AC-3, MP3, CD-RW, MLP,  DTS,  MPEG-2
Compression Formats NOT Supported for
discs inserted into the DVD/CD drive:SACD  Format  (Sony),  DVD-ROM 
						

							5
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 Characteristics:Weight: 2.2 lbs (0.98 kg)
Dimensions: 1.6" H x 5.7" W x 7.6" D
(41.5 mm x 146 mm x 193 mm)
Power  Requirements:+12 Vdc, +5 Vdc
Distortion and Noise:-78 dBFS THD+N, unweighted,
22-22kHz for a 1 kHz signal at FS -1 dB
-90 dBFS THD+N, unweighted,
22-22kHz for a 1 kHz signal at FS -10 dB
Dynamic Range:-90 dBFS THD+N, unweighted,
22-22kHz for a 1 kHz signal at FS -60 dB
Distortion:< 0.1% @ 0.5 W
Output  Noise:< 400 mVrms, A-weighted
Out of Band Noise (greater than 20 kHz):< 1 mVrms, band limited 400 Hz to 300 kHz
Noise when Muted:< 400 uVrms, A-weighted
Parameter Nominal Limit Conditions
Defect tracking (interruption) 1.0 mm 0.8 mm ABEX test disc TCD-725R
Defect tracking (black dot) 1.0 mm 0.8 mm ABEX test disc TCD-725R
Defect tracking (scratch) 1.6 mm 1.0 mm ABEX test disc TCD-721R
Defect tracking (finger print)
75 µm 65 µmABEX test disc TCD-725R
Defect tracking (warped disc) 1.0 mm 0.7 mm ABEX test disc TCD-732R
Defect tracking (eccentric disc)
280 µm 210 µmABEX test disc TCD-714R
Cueing time 2 sec 3 sec Phillips TS4, tracks 1-15 
						

							6
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 0.05% THD
Gain  from  CODEC  0  dBFS:2 Vrms (-6 dB +/- 1 dB)
Output level from FM (mono, 75 kHz dev):0.3 Vrms nominal
Output level from AM (30% mod, 100 dBuV):0.2 Vrms nominal
Source Impedance at 1 kHz:1560 Ohms nominal, +/- 10%
Output  Coupling:AC
S/PDIF Coaxial Input Characteristics:
Sampling Rates Accommodated:44.1  kHz,  48  kHz
Number of bits recognized:16, 20 and 24
Input Impedance:75 Ohms +/- 10%
Error Checking and Handling:Implements full error checking and handling,
considering CRC, validity bit, loss of lock,
parity error, and bi-phase error.
Input Coupling:AC
Optical S/PDIF Input Characteristics:
Sampling Rates Accommodated:44.1 kHz and 48 kHz
Number of bits recognized:16, 20 and 24
Error Checking and Handling:Implements full error checking and handling,
considering CRC, validity bit, loss of lock,
parity error, and bi-phase error.
Input  Connector:TOSLINK
LFE  Channel Volume  Control:+6 dB to -12 dB gain range from the bass
tone control
Film EQ:Selectable on or off
Tone  Controls:Treble Control: Range of -2 to +2 dB in 11 steps
Bass Control: Range of -12 to +6 dB in 18 steps
SPECIFICATIONS 
						

							7
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 nominal / 50 dB limit
Adjacent Channel Selectivity (200 kHz):13 dB nominal / 10 dB limit @ 45 dBf
Alternate Channel Selectivity (400 kHz):70 dB nominal / 65 dB limit @ 45 dBf
Image Rejection:45 dB nominal / 40 dB limit
RF  Intermodulation:65 dB nominal / 55 dB limit
Sub-carrier  Product  Rejection:55 dB nominal / 45 dB limit
Frequency Response:30 Hz to 15 kHz +/- 1.0 dB nominal,
+/- 2.0 dB limit
Stereo Channel Separation @ 1 kHz:35 dB nominal / 25 dB limit
Auto Stop Level (seek):30 dBf +/-5
Mono / Stereo Threshold:40 dBf +/-5
AM Tuner Performance (per IHF-T-100):
Channel Spacing:10  kHz
Band Limits:530 kHz - 1710 kHz
Usable Sensitivity (mono):46 dB nominal / 56 dB limit
Adjacent Channel Selectivity:23 dB nominal / 18 dB limit
Alternate Channel Selectivity:30 dB nominal / 25 dB limit
Image Rejection:40 dB nominal / 35 dB limit
Auto Stop Level:54 dBuV/m +/- 3 dB
Signal to Noise Ratio:50 dB nominal / 45 dB limit
Distortion:0.6% nominal / 1.4% limit
Frequency Response:220 Hz: -3 dB nominal / -6 dB limit
2.0 kHz: -3 dB nominal / -6 dB limit
Bass Module Characteristics:
Woofer Impedance:Single woofer at 1.55 Ohms
Bass Amplifier Distortion Level:< 0.4% THD @ 0.5W
Bass Amplifier Output Noise:< 2 mVrms, unweighted
Bass Amplifier DC Offset:< 50 mVdc 
						

							8
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 
						

							9
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
aligned with the openings in the rear enclo-
sure. Slide the rear enclosure onto the bass
module.
2.2 Using a Phillips-head screwdriver,
replace the four screws (9)  removed in step
1.2.
3. Power Transformer Removal
3.1 Perform procedure 1.
3.2 On the bass module PCB/heatsink
assembly, unplug the cables at J3 and J5
that run to the power transformer. Unplug the
woofer harness jack at J7.
3.3 Using an 8/32" nut driver, remove the
four nuts (6) that secure the power trans-
former (7) to the bass module enclosure.
3.4 Lift the power transformer off of the
mounting studs (5) and out of the enclosure.
4. Power Transformer Replacement
4.1 Align the power transformer (7) with the
mounting studs (5) on the baffle of the bass
module enclosure. Slide the transformer
onto the studs.4.2 Secure the transformer in place using
the four nuts (6) removed in steps 3.3.
4.3 Plug the transformer cables onto J3 and
J5 of the bass module PCB. Plug the woofer
harness cable onto J7.
4.4 Perform procedure 2.
5. Bass Module PCB/Heatsink Assembly
Removal
5.1 Perform procedure 1.
5.2 On the bass module PCB/heatsink
assembly, unplug the cables at J3 and J5
that run to the power transformer. Unplug
the woofer harness jack at J7.
5.3 Using a Phillips-head screwdriver,
remove the four screws (11) that secure the
bass module PCB/heatsink assembly to the
bass module enclosure. Carefully lift it out of
the enclosure.
6. Bass Module PCB/Heatsink Assembly
Replacement
6.1 Align the bass module PCB/heatsink
assembly (10) with the four screw locations
on the bass module enclosure baffle.
6.2 Secure the bass module PCB/heatsink
assembly to the bass module enclosure
using the four screws (11) removed in step
5.3.
6.3 Plug the cables from the power trans-
former (7) onto the connectors at J3 and J5
of the bass module PCB/heatsink assembly.
Plug the woofer cable onto the board at J7.
6.4 Perform procedure 2. 
						

							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 top cover should be sitting on top of
the corresponding latch hole in the rear
panel. Once the center finger has cleared, lift
upward on the rear edge of the top cover
until the four tabs to the sides clear the
console rear panel.
1.2 Slide the top cover to the rear of the
console approximately 1/2". Lift the top cover
off of the console.
2. Top Cover Replacement
2.1 Align the top cover (2) with the console
base (21) so that the concave edge faces
the front of the unit and place it on the top of
the console base with the front edge approxi-
mately 1/2" back from the bezel sub assem-
bly (27).
2.2 Slide the top cover forward, making sure
that the front lip slides under the bezel sub
assembly.
2.3 On the rear panel of the console base,
make sure that the four tabs of the top cover
are inside the rear panel. Using finger pres-
sure only, press inward on the rear panel of
the console base until the top cover finger
snaps into place. The top cover should be
seated evenly across the rear of the con-
sole.3. DVD ROM Drive Removal
3.1 Perform procedure 1.
3.2 On top of the DVD drive (5), you will see
a large spring clamp (3) holding the DVD
drive in place. Using two large flat-tip screw-
drivers, press down and pry the tabs on one
side of the spring clamp away from the
casting (14) at the corners. Lift the spring
clamp off of the DVD drive.
3.3 At the rear of the DVD drive you will see
a shield (4) over the ATAPI (8) and power (7)
cables. There were two types of shields
used in production of the media center, an
adhesive folded metal foil type and a formed
metal shield. If your unit has the folded foil
type, peel the foil back from the rear of the
DVD mechanism until you can access the
cables. If you have the formed metal shield,
lift up the rear of the DVD mechanism and
slide the shield off. Unplug the ATAPI and
power cables from the rear of the DVD
mechanism.
3.4 Lift up on the back of the DVD drive until
the DVD drawer bezel (28) pops off the front
of the DVD drive drawer. You need to lift the
drive up quite a bit to get this to work. Once
the drawer extension is off, slide the DVD
drive to the rear until it is out from under the
edge of the bezel.
3.5 On the underside of the DVD drive,
remove and retain the two small silver
colored Phillips-head screws (6) located
near the front of the drive. These screws are
the ones that protrude from the bottom of the
drive. You will need to install these screws in
the same location on your replacement DVD
mechanism. They are used to physically
align the DVD mechanism in the console
casting (14).