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Bose 20 Manual

Bose 20 Manual

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Last updated 9/20/00
Includes S4, S5, S6, S8, and S9
Updated page 46 on 02/06/2001
Updated page 46, U2 on 9/19/01
Safety Information ............................................................................................................................ 2
Electrostatic Discharge Sensitive (ESDS) Device Handling ........................................................ 3
CD-20 Manual Revision Overview .................................................................................................. 3
Specifications ................................................................................................................................ 4-7
Theory of Operation .................................................................................................................... 8-13
Figure 1. CD-20 Block Diagram ..................................................................................................... 13
Disassembly/Assembly Procedures ....................................................................................... 14-15
Figure 2. Disassembly/Assembly View .......................................................................................... 16
Figure 3. Exploded View of Door ................................................................................................... 17
RC-20 Remote Disassembly/Assembly........................................................................................ 18
Figure 4. RC-20 Disassembly/Assembly View ............................................................................... 18
CD Mechanism Disassembly Procedures ............................................................................... 19-23
Test Procedures ........................................................................................................................ 24-28
Figure 5. Tuner Alignment Locations .............................................................................................. 28
Remote Control Alignment ............................................................................................................ 29
Figure 6. RC-20 Tuning Locations ................................................................................................. 29
Alignment Procedures .............................................................................................................. 30-31
Part List Notes ................................................................................................................................ 32
Main Part List .................................................................................................................................. 33
Figure 7. CD-20 Exploded View ..................................................................................................... 34
CD Mechanism Part List ................................................................................................................ 35
Figure 8. CD Mechanism Exploded View ....................................................................................... 36
Electrical Part List ..................................................................................................................... 37-48
Figure 9. RC-20 Remote Exploded View ....................................................................................... 48
RC-20 Remote Part List ................................................................................................................. 49
RC-20 Remote Electrical Part List ........................................................................................... 49-50
Packaging Part List ........................................................................................................................ 51
Figure 10. Packaging Exploded View ............................................................................................ 51
Accessory Part List ........................................................................................................................ 52
Figure 11. Accessory Packaging ................................................................................................... 52
IC Block Diagrams and Pinouts ............................................................................................... 53-55
CD Mechanism IC Block Diagrams .......................................................................................... 56-59
CD Mechanism IC Pin Configuration Tables .......................................................................... 60-66
CD Mechanism IC and Transistor Voltage Tables .................................................................. 67-68
CD Mechanism Troubleshooting ............................................................................................. 69-86
CD-20 Troubleshooting Waveforms ........................................................................................ 87-91
REV01-02 CHANGED MAGAZINE PART NUMBER
CAUTION: THE BOSE
VICEABLE PARTS. TO PREVENT WARRANTY INFRACTIONS, REFER SERVICE TO
WARRANTY SERVICE STATIONS OR FACTORY SERVICE.
Contents
®
MODEL 20 (CD-20) MUSIC CENTER CONTAINS NO USER-SER-
1

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  • Page 1 CD Mechanism Part List ........................ 35 Figure 8. CD Mechanism Exploded View ..................36 Electrical Part List ........................37-48 Figure 9. RC-20 Remote Exploded View ..................48 RC-20 Remote Part List ......................... 49 RC-20 Remote Electrical Part List ................... 49-50 Packaging Part List ........................

  • Page 2: Safety Information

    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.

  • Page 3: Electrostatic Discharge Sensitive (Esds) Device Handling

    183884-S3) concerning the CD-20. The following PCB assemblies (as well as the original CD- 20 PCB) are covered by this service manual. PCB part number 199827 (has a slight change to the AM circuit to enable the use of a new AM antenna), PCB part number 250736 (incorporates...

  • Page 4: Specifications

    SPECIFICATIONS Physical Dimensions: 2.6"H x 15.5"W x 8"D (6.6 x 39.4 x 20.3 cm) Weight: 5.9 lbs. (2.7kg) Top Cover: Brushed aluminum finish Bottom Cover: Plastic, Black Display: Vacuum fluorescent Power Input: 5mm coaxial power jack Detachable power-pack, 12VAC, 1.6A...
  • Page 5 SPECIFICATIONS FM Tuner (per IHF-T-200) (continued) 50 dB Quieting Sensitivity; Mono: US: 15 dBf nominal/ 20 dBf limit EURO: 20 dBf nominal/ 25 dBf limit JAPAN: 20 dBf nominal/ 25 dBf limit Stereo: US: 37 dBf nominal/ 42 dBf limit...
  • Page 6 Channel Separation: 70 dB nominal/ 50 dB limit at 1 kHz ± 0.5 dB nominal/ ± 1.0 dB limit Frequency Response: 20 Hz - 20 kHz Low-level Linearity Error: 5.0 dB nominal/ 10.0 dB limit -90 dB Dynamic Range: 95 dB nominal/ 90 dB limit...
  • Page 7 SPECIFICATIONS CD Player (continued) Defect Tracking (interruption): 1.0 mm nominal/ 0.8 mm limit ABEX Test Disk TCD-725R Defect Tracking (black dot): 1.0 mm nominal/ 0.8 mm limit ABEX Test Disk TCD 725R Defect Tracking (scratch): 1.6 mm nominal/ 1.0 mm limit ABEX Test Disk TCD-721R 75 µm nominal/ 65 µm limit Defect Tracking (finger print):...

  • Page 8: Theory Of Operation

    THEORY OF OPERATION 1.0 Overview The CD-20 is a self-contained CD player with a 6-disc changer, AM/FM tuner, preamplifier, and ® control center for use with Bose powered speaker systems. In addition to the two internal sources (CD and tuner), it allows for up to four external audio sources to be connected (Tape, Aux, Video 1 and Video 2).
  • Page 9 P7, P8 and P9. The CD-20 display is divided into 8 groups, each enabled by a separate grid line (G1 through G8). Each of these groups contains up to 15 icons. Each icon is enabled by a separate segment line (S1 through S15).
  • Page 10 Zone 2 fixed audio outputs. Output #3 from U101 (pins 16 and 17) is used for the CD-20’s left and right Tape output. The micro sees to it that this output nominally is connected to the same input source as the Zone 1 output.
  • Page 11 (as described above). The #2 output of the Zone 1 volume chip is used for CD-20’s Headphone output (the #2 output on the Zone 2 chip is not used). Anyone plugging in headphones would therefore hear the same source that was previously being played by the Zone 1 speakers.
  • Page 12 THEORY OF OPERATION 5.0 Tuner Electronics (continued) The signal from the AM loop antenna enters the unit through the 2.5 mm AM jack (J300) and is fed to the AM front end module (T302). This device contains an RF tuned section and the AM local oscillator tuner circuit.
  • Page 13 THEORY OF OPERATION Figure 1. CD-20 Block Diagram...
  • Page 14 Push the cover (1) down until it is fully (2) until it snaps into the base (9). seated. ® Note: Align the cover so that the BOSE 6.3 Redress the ribbon cable in the logo is in the left corner. channel at the rear of the superstructure (2).
  • Page 15 13.2 Grasp the PCB assembly (18) and lift it straight up. 13.3 The RCA jack PCB (19) and the headphone PCB (20) are wired to the PCB assembly. Lift the RCA Jack PCB and the headphone PCB straight up. Note: When removing the PCB, make a...
  • Page 16 Figure 2. Disassembly/Assembly View...
  • Page 17 HINGE FRONT VIEW HINGE HOLDER Figure 3. Exploded View of Door...

  • Page 18: Remote Disassembly/Assembly

    (4) so that the buttons line up with the holes in the top cover. 2.1 Lower the bottom cover (3) onto the top cover (4) so that the bottom cover's lip fits over the top cover. CATCHES CATCHES Figure 4. RC-20 Disassembly/Assembly View...

  • Page 19: Cd Mechanism Disassembly Procedures

    CD MECHANISM DISASSEMBLY PROCEDURES 1. Main PCB Disassembly 1.1 Short the two pads on the ribbon cable coming from the pick up. 1.2 Unplug CN905. 1.3 Remove the four screws that secure the PCB to the chassis. 1.4 Lift the PCB up and remove the remain- ing connectors.
  • Page 20 CD MECHANISM DISASSEMBLY PROCEDURES Note: When installing the mount chassis (A173), line up the elevator shaft (A119) so that the lever (A55) is almost touching the eject lever (A45). The mount chassis should be at it's lowest position. 3. Elevator Motor Disassembly 3.1 Unplug the FPC (A104) from the PCB.
  • Page 21 CD MECHANISM DISASSEMBLY PROCEDURES 4. Feed Motor Disassembly 4.1 Remove the washer (A102) and then remove the DV middle gear (A81). 4.2 Remove the FPC from the feed motor with a soldering iron. 4.3 Remove the two screws (A94) that secure the feed motor (A89).
  • Page 22 CD MECHANISM DISASSEMBLY PROCEDURES 6. Lift Motor Disassembly 6.1 Perform procedure 3. 6.2 Remove the two DL springs (A228) that are located on both sides. The DL springs are black. 6.3 Remove the FPC from the lift motor (A154) with a soldering iron. 6.4 Grasp the unit where the DL springs were located and rotate the motor assem- bly section up.
  • Page 23 CD MECHANISM DISASSEMBLY PROCEDURES Note: When replacing the pickup, grease the main shaft and the U groove of the sub shaft. After securing the FPC, apply glue to the end opposite the screw. 8. Manual Magazine Ejection 8.1 With the disc clamped, rotate the lift motor worm gear (A148) 25 to 28 turns in the direction of the arrow to unclamp the disc.

  • Page 24: Test Procedures

    TEST PROCEDURES General Test Setup 2. Video Gain And Separation Test Use cable 184209 for fixed level tests. Use cable 183174 for adjustable level tests. 2.1 Apply a 2 Vrms, 1 kHz signal to the left The miniature switch number 8 on the VIDEO 1 input.
  • Page 25 8.3 and (should be ± 1 dB). 8.4. Recheck FM distortion. 6.4 Apply a 1 Vrms, 20 kHz signal to the AUX input. 9. FM Stereo Separation 6.5 Reference a dB meter to the applied 9.1 Inject an RF signal into the FM an-...
  • Page 26 TEST PROCEDURES 12.4 Tune the generator and the unit to 10. FM Stop Level Adjustment 1080 kHz. Adjust the brown slug of T302 Note: Do not perform the following test for for maximum output. PCB 250736. 12.5 Repeat steps 12.3 and 12.4 until 10.1 Inject an RF signal into the FM an- maximum output is obtained.
  • Page 27 TEST PROCEDURES 15. CD Tracking Ability 15.1 The test discs listed in the chart below should be played with no audible defects. 15.2 If the unit fails any of these tests, replace the CD mechanism assembly or proceed to the Alignment procedures. Disc Test Test Conditions...
  • Page 28 TEST PROCEDURES PCB 178335 PCB 199827 PCB 250736 Figure 5. Tuner Alignment Locations...

  • Page 29: Remote Control Alignment

    1.4 Rotating C14 360 degrees, you should see two points where the signal peaks. Adjust C14 until the output at TP22 is peaked ( ≥ 6Vpp). It doesn't matter which peak you tune to. 1.5 TP19 should be 3 Vpp. TP20 should be 1 Vpp. Figure 6. RC-20 Tuning Locations...

  • Page 30: Alignment Procedures

    Perform these procedures in exact order! 1. FE Bias Alignment Figure 1. FE Bias Alignment 1.1 Connect the power pack to the CD-20 and leave the CD-20 in the OFF mode. Changer PCB 1.2 Connect a DC voltmeter to TP824 (FE TP705 out) and TP704 (1/2 Vcc).
  • Page 31 Figure 5. Symmetrical Waveform labeled TE and connect the alignment fixture as shown in Figure 4. 4.3 Plug the CD-20 in and play track num- ber 1 of the A•Bex CD TCD-784. 4.4 Switch the CD-20 alignment fixture's oscillator to 2.15 kHz.

  • Page 32: Part List Notes

    6. This part is used on the 178335 PCB only. The 178335 PCB is the original PCB used on the CD-20. Most of the parts listed are common to all of the PCB variants. 7. This part is used on the European variant.

  • Page 33: Main Part List

    MAIN PART LIST (Refer to Figure 7) Item Description Part Q t y . Note Number Number COVER, TOP 180038 SCREW, TAPP, 6-13 X .875, PAN, XREC 187426-14 SUPERSTRUCTURE 250257 PCB, ASSEMBLY 271911-101CK 1,4, 271911-101C or without BASE ASSY 183889-001 connector kit SPRING, MOUNTING, CD-MECH 184041...
  • Page 34 Figure 7. CD-20 Exploded View...

  • Page 35: Cd Mechanism Part List

    Note: The table above lists all the parts that are available for the CD changer mechanism portion of the CD-20. The part numbers that are not proceeded by a letter represent an assem- bly that is outlined in Figure 8. Part numbers that are preceded by a letter represent individual...
  • Page 36 Figure 8. CD Mechanism Exploded View...

  • Page 37: Electrical Part List

    ELECTRICAL PART LIST Resistors Reference Designator Description Part Number Note 82 OHM, 2512, 1W, 5% 181895-82R0 7.5 OHM, 2512, 1W, 5% 181895-7R5 130 OHM, 2512, 1W, 5% 181895-1300 910 OHM, 1206, 1/8W, 5% 124895-9115 2.0K, 2512, 1W, 5% 181895-2001 2.7K, 2512, 1W, 5% 181895-2701 330 OHM, 0805, 1/10W, 5% 133626-3315...
  • Page 38 ELECTRICAL PART LIST Resistors (continued) Reference Designator Description Part Number Note R147 220 OHM, 0805, 1/10W, 5% 133626-2215 R148 10.0K, 0805, 1/10W, 5% 133626-1035 R152 4.7K, 0805, 1/10W, 5% 133626-4725 R161 100K, 0805, 1/10W, 1% 133625-1003 R162 100K, 0805, 1/10W, 1% 133625-1003 R163 100K, 0805, 1/10W, 1%...
  • Page 39 ELECTRICAL PART LIST Resistors (continued) Reference Designator Description Part Number Note R325 2.7K, 0805, 1/10W, 5% 133626-2725 R326 8.2K, 0805, 1/10W, 5% 133626-8225 R326 3.09K, 0805, 1/10W, 1% 133625-3091 R328 12K, 0805, 1/10W, 5% 133626-1235 R329 5.11K, 0805, 1/10W, 1% 133625-5111 R330 10 OHM, 0805, 1/10W, 5%...
  • Page 40 ELECTRICAL PART LIST Resistors (continued) Reference Designator Description Part Number Note R406 1.00K, 0805, 1/10W, 5% 133626-1025 R408 100 OHM, 0805, 1/10W, 5% 133626-1015 R409 1.00K, 0805, 1/10W, 5% 133626-1025 R410 10.0K, 0805, 1/10W, 5% 133626-1035 R411 1.00K, 0805, 1/10W, 5% 133626-1025 R412 1.00K, 0805, 1/10W, 5%...
  • Page 41 Reference Designator Description Part Number Note .01uF, 100V, 20% 180630-103 .01uF, 0805, X7R, 50V, 10% 133623-103 470uF, EL, 85°C, 25V, 20% 149948-471E .047uF, 0805, Z5U, 20% 148779-473 .01uF, 0805, X7R, 50V, 10% 133623-103 470uF, EL, 85°C, 25V, 20% 149948-471E 10uF, EL, 85°C, 25V, 20% 149947-100E .01uF, 0805, X7R, 50V, 10%...
  • Page 42 Description Part Number Note .01uF, 0805, X7R, 50V, 10% 133623-103 .01uF, 0805, X7R, 50V, 10% 133623-103 100uF, EL, 85°C, 50V, 20% 149948-101H .01uF, 0805, X7R, 50V, 10% 133623-103 100uF, EL, 85°C, 50V, 20% 149948-101H 100uF, EL, 85°C, 50V, 20% 149948-101H .01uF, 0805, X7R, 50V, 10%...
  • Page 43 180pF, 0805, COG, 50V, 5% 133622-181 C143 1000pF, 0805, COG, 50V, 5% 133622-102 C144 180pF, 0805, COG, 50V, 5% 133622-181 C145 470uF, EL, 85°C, 25V, 20% 149948-471E C145 1000uF, EL, 85°C, 16V, 20% 149948-102C C146 100pF, 0805, COG, 50V, 5% 133622-101 C200...
  • Page 44 ELECTRICAL PART LIST Capacitors (continued) Reference Designator Description Part Number Note C324 39pF, 0805, COG, 50V, 5% 133622-390 C325 10uF, EL, 85°C, 25V, 20% 149947-100E C326 470pF, 0805, COG, 50V, 5% 133622-471 6, 7 C326 100pF, 0805, COG, 50V, 5% 133622-101 C327...
  • Page 45 Capacitors (continued) Reference Designator Description Part Number Note C420 39pF, 0805, COG, 50V, 5% 133622-390 C421 47uF, 85°C, 16V, EL, 20% 178198-470C C422 2.2uF, 1206, Y5V, 16V, 80% 178212-225 C423 .047uF, 0805, Z5U, 20% 148779-473 C432 .01uF, 0805, X7R, 50V, 10%...
  • Page 46 177983 U103 NJN3404AM, OP AMP 181080 U104 NJM4556, OP AMP, DUAL, SO-8 148598 U300 LA1851, DIGITAL TUNER, DIP-30 146815 U302 PLL FREQ SYNTH, DIP-20 147527 U303 NJN3404AM, OP AMP 181080 U400 TMP87XX0, uC, QFP80 199455-001 U401 24C01A, EEPROM 184044 U402...
  • Page 47 ELECTRICAL PART LIST Transformers Reference Designator Description Part Number Note CF300 FILTER, CER., 10.7MHz, 280 kHz 253037-001 CF300 FILTER, CER., 10.7MHz, 230 kHz 253037-002 CF301 FILTER, CER., 10.7MHz, 280 kHz 253037-001 CF301 FILTER, CER., 10.7MHz, 230 kHz 253037-002 CF302 FILTER, CER., 10.7MHz, 280 kHz 253037-001 CF302 FILTER, CER., 10.7MHz, 230 kHz...
  • Page 48 SWITCH, TACTILE DOME, 160gf 172999-02 Crystals Reference Designator Description Part Number Note X300 RESONATOR, CERAMIC, 456KHz 147233 X301 CRYSTAL, QUARTZ, 7.2MHz, 50PPM 147223 or 197680 11/02 X401 CRYSTAL, CERAMIC RESONATOR, 175627 8MHz CATCHES CATCHES Figure 9. RC-20 Remote Exploded View...

  • Page 49: Remote Part List

    (Refer to Figure 9) Item Description Part Qty Per Note Number Number Assembly PCB Assembly 194386 1, 2 Pad, Switch, Remote, RC 20, 178379 Audio Cover, Bottom, Remote 146089 Control Cover, Top, Remote Control, 176190 Universal Door, Battery, Remote 146226 Control...
  • Page 50 RC-20 REMOTE ELECTRICAL PART LIST Capacitors Reference Designator Description Part Number Note 10 µF, 16v, 20% 177902-100C .047 µF, 50V, 20% 148779-473 100 pF, 50V, 5% 133622-101 100 pF, 50V, 5% 133622-101 .047 µF, 50V, 20% 148779-473 1000 pF, 50v, 5% 133622-102 .01 µF, 50V, 10%...

  • Page 51: Packaging Part List

    PACKING, INSERT D/C CARD 188022 SCREW, SHIPPING, CD MECH. 198583 PACKING, TOP PAD, EPS 186424-001 PACKING, TRAY, EPS 186425-001 CARTON, D/C, CD-20 188020-001 BAG, MICROFOAM, 18 x 10.5 174591 MAGAZINE, 6 DISC 256261 REMOTE 178915 Figure 10. Packaging Exploded View...

  • Page 52: Accessory Part List

    ACCESSORY PART LIST Item Description Part Q t y . Note Number Number POWER PACK, 100V 178372 POWER SUPPLY, 120V 178371 POWER PACK, 220V, EURO 178375 POWER PACK, 230V, UK/SING. 251773 POWER PACK, 240, AUST. 178373 REMOTE 187700 MAGAZINE, 6 DISC 263040 10/01 PACKING TRAY...

  • Page 53: Ic Block Diagrams And Pinouts

    IC BLOCK DIAGRAMS AND PINOUTS U101 Part Number 177984-2...
  • Page 54 IC BLOCK DIAGRAMS AND PINOUTS U100, 102 Part Number 177938...
  • Page 55 IC BLOCK DIAGRAMS AND PINOUTS U302 Part Number 147527 U300 Part Number 146815...

  • Page 56: Cd Mechanism Ic Block Diagrams

    CD MECHANISM IC BLOCK DIAGRAMS IC 821 (CXA1782BQ) Servo Signal Processor RF Amplifier...
  • Page 57 CD MECHANISM IC BLOCK DIAGRAMS ATTN MODN TSTN LRCI Input Interface DCKI Filter Calculate Infinity Attenuation Zero Detect Calulate Block DFS1 XVSS DFS2 Timing Control MUTEO Noise Shaper PWM Data Calculate Generation Block Block RSTN XVDO DVSS DVDD AVDO4 AVDO1 18 19 21 22 IC 201 (SM5871AS) D/F and D/A Converter...
  • Page 58 CD MECHANISM IC BLOCK DIAGRAMS (8) Vcc ---- (4) Vss----- Start Cycle H.V. Generation Timining and Control (5) SDA Start Stop Logic Control Logic Load (6) SCL C Prom XDEC Word 32 X 32 Address Counter YDCC Dout Data Register D out IC 602 (X204C01SI) IC 861 (BA6398FP) CD Driver and +5V Regulator...
  • Page 59 CD MECHANISM IC BLOCK DIAGRAMS Basic Bit SEQ. Interval Buffer:16 Timer Program INTBT Counter SP (8) Port 0 P00-P03 Timer/Event Counter PT100/P20 P10-P13 Port 1 INTTO Bank Timer/Event Counter Port 2 P20-P23 PT01/P21 INTT1 P30-P33 Port 3 S1/PO3 Serial General Reg. SO/PO2 Interface _______...

  • Page 60: Cd Mechanism Ic Pin Configuration Tables

    CD MECHANISM IC PIN CONFIGURATION TABLES IC 201 (SM5871AS) D/F and D/A Converter Table I / O Terminal Description Name Crystal oscillator output XVss Clock ground CKSLN Clock frequency select input. Internal pull-up resistor Clock output TSTN Test input. This pin should be tied HIGH for normal operation.
  • Page 61 CD MECHANISM IC PIN CONFIGURATION TABLES IC 601 (uPD75116GF-K12) Microprocessor Table (continued) I / O Terminal Description Name TEMP Thermosensor input EJECTS Eject switch input ACCIN Acc ON/OFF input LOMP Loading motor output LOMN Loading motor output ELEVMN Elevator motor output ELEVMP Elevator motor output RESET LSI reset signal...
  • Page 62 CD MECHANISM IC PIN CONFIGURATION TABLES IC 601 (uPD75116GF-K12) Microprocessor Table (continued) I / O Terminal Description Name LIFTSW Lift switch input COMDO Correspondence data output Power supply of PROM writing Power supply (+5V) CDINOK CD mechanism in switch input CD+B Divider unit control signal Clock output for S-RAM data reading...
  • Page 63 CD MECHANISM IC PIN CONFIGURATION TABLES IC 801 (CXD2517Q) Digital Signal Processor Table I / O Terminal Description Name Focus OK input. Used for SENS output and the servo auto sequencer Spindle motor servo control Test Test pin. Normally GND. FILO Master PLL (slave=digital PLL) filter output.
  • Page 64 CD MECHANISM IC PIN CONFIGURATION TABLES IC 801 (CXD2517Q) Digital Signal Processor Table (continued) I / O Terminal Description Name SCOR Outputs high signal when either subcode sync S0 or S1 is detected. S Q S O SubQ 80-bit serial output. SQCK SQSO readout clock input.
  • Page 65 CD MECHANISM IC PIN CONFIGURATION TABLES IC 821 (CXA1782BQ) Servo Signal Processor RF Amplifier Table (continued) I / O Terminal Description Name TA_M Tracking amplifier negative input pin. TA_O Tracking drive output SL_P Sled amplifier non-inversed input. SL_M Sled amplifier negative input pin. SL_O Sled drive output.
  • Page 66 CD MECHANISM IC PIN CONFIGURATION TABLES IC 821 (CXA1782BQ) Servo Signal Processor RF Amplifier Table (continued) I / O Terminal Description Name I-V amplifier E gain adjustment. (When not using automatic balance adjustment) Tracking error amplifier output. E-F signal is output. LPFI Comparator input for balance adjustment.

  • Page 67: Cd Mechanism Ic And Transistor Voltage Tables

    CD MECHANISM IC AND TRANSISTOR VOLTAGE TABLES Condition: DC voltage at stop mode. Voltage readings from common ground are measured with a digital voltmeter. Pin\Xistor Q201 Q202 Q203 Q204 Q205 Q601 Q602 Q701 Q702 Q703 Q704 14.4 14.4 14.4 14.2 14.4 14.4 14.4...
  • Page 68 CD MECHANISM IC AND TRANSISTOR VOLTAGE TABLES IC801 12 13 16 17 2.5 2.5 NC NC 23 24 27 28 31 32 35 36 NC NC NC NC NC NC NC NC NC NC NC 42 43 46 47 50 51 54 55 NC NC 61 62...

  • Page 69: Cd Mechanism Troubleshooting

    CD MECHANISM TROUBLESHOOTING...
  • Page 70 CD MECHANISM TROUBLESHOOTING...

  • Page 71: Troubleshooting

    TROUBLESHOOTING...
  • Page 72 CD MECHANISM TROUBLESHOOTING...
  • Page 73 CD MECHANISM TROUBLESHOOTING...
  • Page 74 CD MECHANISM TROUBLESHOOTING...
  • Page 75 CD MECHANISM TROUBLESHOOTING...
  • Page 76 CD MECHANISM TROUBLESHOOTING...
  • Page 77 CD MECHANISM TROUBLESHOOTING...
  • Page 78 CD MECHANISM TROUBLESHOOTING...
  • Page 79 CD MECHANISM TROUBLESHOOTING...
  • Page 80 CD MECHANISM TROUBLESHOOTING...
  • Page 81 CD MECHANISM TROUBLESHOOTING...
  • Page 82 CD MECHANISM TROUBLESHOOTING...
  • Page 83 CD MECHANISM TROUBLESHOOTING...
  • Page 84 CD MECHANISM TROUBLESHOOTING...
  • Page 85 CD MECHANISM TROUBLESHOOTING...
  • Page 86 CD MECHANISM TROUBLESHOOTING...

  • Page 87: Troubleshooting Waveforms

    CD-20 TROUBLESHOOTING WAVEFORMS...
  • Page 88 CD-20 TROUBLESHOOTING WAVEFORMS...
  • Page 89 CD-20 TROUBLESHOOTING WAVEFORMS...
  • Page 90 CD-20 TROUBLESHOOTING WAVEFORMS...
  • Page 91 CD-20 TROUBLESHOOTING WAVEFORMS...
  • Page 93 ® LIFESTYLE MODEL 20 MUSIC CENTER (CD-20) Service Manual © 1999 Bose Corporation Part Number 183884 REV. 02...
  • Page 94 SPECIFICATIONS AND FEATURES SUBJECT TO CHANGE WITHOUT NOTICE ® ® Bose Corporation The Mountain Framingham Massachusetts USA 01701 P/N 183884 REV. 02 09/99 FOR TECHNICAL ASSISTANCE OR PART ORDERS, CALL 1-800-367-4008...
  • Page 95 ® ® ® Powered Acoustimass Speaker System AM-25P Supplement PCB # 188574 PCB # 193227 © 1997 Bose Corporation Service Manual Part Number 177870-S4 REV 00...

  • Page 96: Table Of Contents

    Part List Notes ..........................34 PCB Identification .......................... 34 Main Part List ..........................35 Figure 20. Bass Module Exploded View ..................36 Figure 21. Module Assembly Exploded View ................. 36 Electrical Part List ........................37-42 Satellite Part List ..........................43 Figure 22.

  • Page 97: Safety Information

    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.

  • Page 98: Electrostatic Discharge Sensitive (Esds) Device Handling

    ® 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.

  • Page 99: Specifications

    SPECIFICATIONS Dimensions: Module: 23.3"W x 7.5"D x 14.0"H (59 x 19 x 35.5cm) Satellite: 3.0"W x 4.8"D x 6.0"H (7.6 x 12.2 x 15.2cm) Weight: Module: 33lbs. (15kg.) Satellite: 1.3lbs. (0.6kg.) Packed System: 27lbs. (12.3kg.) Module: 5-1/4" Woofers, 8Ω (parallel) Satellites: 2-1/4"...

  • Page 100: Theory Of Operation

    2. GENERAL OPERATION AND BLOCK DIAGRAM OVERVIEW Connection to the CD-20 occurs through a 30 ft. shielded audio cable which carries the follow- ing signals: • Left and right stereo audio (shielded) •...
  • Page 101 THEORY OF OPERATION 2.2 Surround Decoder Surround channel information is audio that is recorded 180° out of phase (+90° left and -90° right) on to the left and right channels (in equal amplitude). On movie soundtracks this typically represents special effect sounds that are meant to be heard behind the listener. Center chan- nel information (movie dialogue for instance) is audio that is recorded in equal amplitude on to left and right channels that is in phase (0°...
  • Page 102 3. DETAILED THEORY OF OPERATION 3.1 Power Supply The 10 Volt DC turn-on signal from the CD-20 is received at pin 1 of DIN connector J5. It is direct coupled to the base of Q601. When the AM-25P receives the “turn-on pulse” from the CD-20, Q604 and Q601 conduct and provide a current path through opto-coupler U604.
  • Page 103 The differential input amplifier stage (op-amp U13, pins 1, 2 and 3) buffers and preamplifies the CD-20 output signal. Gain is limited to 10.6dB to prevent potential overload (from the maxi- mum 2Vrms input signal). Capacitors C102, C103, C104 and C162 are for suppression of Radio Frequency Interference (RFI).
  • Page 104 CENTER CHANNEL FREQUENCY RESPONSE FREQUENCY- - HERTZ Figure 1. Center Channel Frequency Response SURROUND CHANNEL FREQUENCY RESPONSE FREQUENCY- - HERTZ Figure 2. Surround Channel Frequency Response...
  • Page 105 BASS CHANNEL LEFT/RIGHT CHANNEL FREQUENCY- - HERTZ Figure 3. Bass and Left/Right Channel Frequency Response - 10 - 15 - 20 - 25 - 30 - 35 DYNAMIC EQUALIZER FREQUENCY RESPONSE - 40 FREQUENCY- - HERTZ Figure 4. Dynamic Equalizer Frequency Response...
  • Page 106 THEORY OF OPERATION 3.3 Surround Detector Output from differential amplifier U13 is applied to a pair of 85Hz 1st order high pass filters, one inverting, the other non-inverting. The inverting stage facilitates full wave detection in the next stage. This output is sent to full wave negative peak detector stage U700. U700 is a quad comparator with open collector output that can only sink current, and thus (with capacitor C706) acts as a negative peak detector with fast attack and medium (30ms) decay through 3 kΩ...
  • Page 107 THEORY OF OPERATION 3.4 Decoder Gain Cell (Refer to Schematic Diagram Sheet 2) The output of the treble control stage is applied to the input of the surround sound decoder. The decoder is made up of several stages that include U10, U11, U12, and U14. At the input of the decoder, left and right audio channels are converted to L+R and L-R signals through summing amplifier U10, pins 1, 2 and 3 and differential amplifier U10, pins 12,13 and 14, respectively.
  • Page 108 Efficiency is typically increased from 20% to 40%, and power dissipation is reduced by a factor of 2.5. Detailed operation is as follows: Referring to sheet 3 of the schematic, audio input is applied to the Amplifier PCB at pin 8 of connector J2 and is AC coupled through C388.
  • Page 109 THEORY OF OPERATION When the audio output voltage approaches the 17VDC power supply rail, output transistor Q382 begins to saturate and conducts much more base current than the normal maximum of 5mA. At approximately 8mA the voltage drop across 75Ω resistor R390 exceeds 0.6V and small signal transistor Q383 begins to conduct.
  • Page 110 Figure 5. Voltage at Collector of Q381 (Bass Amplifier) Figure 6. Treble Control Frequency Response...
  • Page 111 10VDC turn-on pulse is reissued from the CD-20. This only happens if the CD-20 is powered off and then back on, which can be done through the remote control. The protection circuits that tie into the...
  • Page 112 THEORY OF OPERATION The thermal detect line feeds into pin 9 of the microcontroller. This is the output of a compara- tor that incorporates a thermistor to monitor the temperature of the amplifier PCB near the heat sink. At room temperature (25°C) the thermistor resistance is 22kΩ. It forms a voltage divider with resistor array R608 (pins 3-4), and a mirrored voltage divider exists R608 (pins 1-2) with R607 on the inverting input of the comparator (U600 pins 1, 6 and 7).
  • Page 113 Figure 7. Simplified Block Diagram of Shared 2 Channel Class-G Amplifier...
  • Page 114 Figure 8. PCB Block Diagram...
  • Page 115 L out DC CONTROL DETECTOR L in C out DUAL VOL. CTL. S out DC CONTROL R in B out R out...

  • Page 116: Disassembly/Assembly Procedures

    DISASSEMBLY/ ASSEMBLY PROCEDURES Bass Module enclosure with your right-hand fingers. Note: Numbers in parentheses correspond to the callouts in the Figures referred to in the 1.7 Press the module's right base-plate tab following procedures. down with a scribe or small flat-head screwdriver.
  • Page 117 DISASSEMBLY/ASSEMBLY PROCEDURES Note: Numbers in parentheses correspond 4. Main PCB Assembly Replacement to the callouts in the Figures referred to in the following procedures. 4.1 Place the main PCB (5) onto the adapter bracket (6) component side down. 2. Cover Replacement The J5, J9, and J11 input and output connectors should be facing the label side 2.1 Place the cover (1) over the module...
  • Page 118 Input and Output Connectors Module Label Side Input and Output Connectors Figure 14. Module Enclosure Disassembly Back of Module Cover Open Close Cover Latch Base Plate Tabs Base Plate Tabs Figure 15. Cover Assembly...
  • Page 119 Voltage Select Switch for 115/230V Units Back of Cover Not Applicable for -13, -23, -63 Module Assemblies J8 Connector Main PCB J10 Connector, 8-Pin Cable Input and Output J5,J9,J11 Connectors Cover Latch Adhesive Side Towards (2X) the Transformer 5-Pin J7 Connector Flat Ribbon Cable Base Plate Heatsink/Amplifier PCB...
  • Page 120 DISASSEMBLY/ASSEMBLY PROCEDURES Note: Numbers in parentheses correspond 6.4 Press down on the metal plate quickly to the callouts in the Figures referred to in the with both palms of your hand. The plate following procedures. Refer to Figures 14, 16, should snap into the slot of the heatsink.
  • Page 121 Refer to Figures 14 and 10.1 Strip the ends of the module's wiring harness (9). Connect the yellow wire to the replacement woofer's (20) + positive termi- 8. Transformer Replacement nal and the green wire to the - negative terminal.
  • Page 122 DISASSEMBLY/ASSEMBLY PROCEDURES 5. Connector Removal Cube Array (Satellite) Procedures 5.1 Perform procedures 1 and 3. Note: Numbers in parentheses correspond to the callouts in Figure 19. 5.2 Remove the polyester batting (9) from the inside of the cube. 1. Grille Assembly Removal 5.3 Place a flat-blade screwdriver inside 1.1 Swivel the cube array so that the grille the cube enclosure and insert the blade...

  • Page 123: Test Set-Up Parameters

    TURN-ON Apply AC mains voltage. Wait 100ms and apply +10VDC between J5 Pin 1 and 7, or (if connected) power CD-20 on. Pin 7 is the ground reference point which has to be connected. MANUAL TEST MODE The microcontroller can be manually configured to operate in several different "Test Modes" to facilitate input/output troubleshooting and repair without the need for a CD-20 music center (to provide serial data commands to the microcontroller).

  • Page 124: Test Procedures

    TEST PROCEDURES Output Measurement Note: Use test mode B unless otherwise Right Channel 0dB (Reference) ≤ -12dBr noted. Use the AM-9P audio cable 176199 Center Channel ≤ -12dBr to connect test equipment to the AM25P. Surround Channel ≤ -16dBr Left Channel 1.

  • Page 125: Frequency Response

    TEST PROCEDURES FREQUENCY RESPONSE 9. Center Channel Frequency Response 7. Bass Channel 9.1 Apply a 1.0kHz, 50mVrms signal to the left and right inputs (in phase). 7.1 Apply a 100Hz, 54mVrms signal to the left and right inputs (in phase). 9.2 Reference a dB meter to the center channel output.

  • Page 126: Amplifier Test

    TEST PROCEDURES 11. Dynamic Equalization (volume control 14. Large Signal Distortion dependent). Note: Resistor loads connected only to the Note: Use test mode D. channel under test. Channel Input Freq. Distortion 11.1 Apply a 50Hz, 1Vrms signal to the left Bass 260mVrms 100Hz...
  • Page 127 "whooshing" noise, there is probably an air leak. Repair air leaks as required. 20. Tone Control Test 20.1 Apply a 100Hz 40mVrms signal to the audio input. Rotate the bass control fully clockwise and counterclockwise from its center position. The frequency response should increase and decrease smoothly without making any scratchy noise.

  • Page 128: Part List Notes

    PART LIST NOTES 1. This part is not normally available from Customer Service. Approval from the Field Service Manager is required before ordering. 2. The individual parts located on the PCBs are listed in the Electrical Parts Lists. This part is critical for safety purposes. Failure to use a substitute replacement with the same safety characteristics as the recommended replacement part might create shock, fire and or other hazards.

  • Page 129: Main Part List

    MAIN PART LIST (see Figures 20 and 21) Item Desciption Part Qty Note Number Number COVER, AM9P, REG, WHITE 172278-11 COVER, AM9P, REG, BLACK 172278-12 KNOB, TONE CONTROL, WHITE 172289-1 KNOB, TONE CONTROL, BLACK 172289-2 LATCH, COVER 172294 BASE PLATE...
  • Page 130 Figure 20. Bass Module Exploded View Voltage Select Switch for 115/230V Units Not Applicable for -13, -23, -63 Module Assemblies (2X) MAIN PCB (2X) Figure 21. Module Assembly Exploded View...

  • Page 131: Electrical Part List

    294, 322, 378, 380, 387, 494, 594, 606, 614, 621, R16, 17, 401, 501 8.25KΩ, CHIP, 0805, 1% 133625-8251 R18, 20, 309, 386, 637, 639 4.42KΩ, CHIP, 0805, 1% 133625-4421 R19, 21, 156, 157, 256, 257, 499Ω, CHIP, 0805, 1% 133625-4990...
  • Page 132 3.01KΩ, CHIP, 0805, 1% 133625-3011 224, 275, 277, 381, 385, 475, 477, 575, 577, 708, 721, 722, R127, 128, 227, 228, 407, 20.0KΩ, CHIP, 0805, 1% 133625-2002 452, 454, 463, 507, 514, 554, 604 R138, 238, 311, 320, 321, 301Ω, CHIP, 0805, 1%...
  • Page 133 Number C1, 2, 123, 223, 407, 507 .033uF, 0805, X7R, 50V, 10% 133623-333 C3, 4 4700uF, EL, BP, 85, 50V, 20% 187394 C5, 6, 11, 12, 18-20, 28-43, .10uF, 0805, Y5V, 25V, 80% 133624 46-51, 54, 55, 58, 59, 185,...
  • Page 134 Part Note Designator Number C175, 275, 388, 475, 575, 1.0uF, EL, 20% 137126-1R0 604, 606 C181, 281, 481, 581 10uF, EL, 85, 25V, 20% 149947-100 C302 680pF, MONO, COG, 50V, 5% 140564-681 C303 .056uF, BOX, 85, 63V, 5% 137127-563 C304 .0027uF, BOX, 85, 100V, 5%...
  • Page 135 ELECTRICAL PART LIST Transistors Reference Description Part Note Designator Number Q177, 179, 277, 279, 379, PNP, SMALL 119168 385, 386 Q175, 180, 275, 280, 377, NPN, TAPE 117921 380, 383, 384, 601 Q176, 276, 381, 382 DARL, P, TIP146T 172285 Q178, 278, 387, 388 DARL, N, TIP141T 172284...
  • Page 136 135091-070 FUSE CLIP, 5mm 178548 L600 INDUCTOR, LM4532, 1uH 178370-1R0 F601 FUSE, 5X20mm, SLO-BLO, 3M 263041-3000 R5, 6 20 OHM, FUSING, 1/4W 130102-200 20K, THERMISTOR, ERTD 3FH 177557 L 203 R50, 306 10K, POT, DUAL, DETENT. 185173 R100, 200, 645 1.0KΩ, ARRAY, SMT, 4 POS,...

  • Page 137: Satellite Part List

    SATELLITE PART LIST Item Description Part Note Number Number O-Ring 141403 Washer, Flat, Black 141402-1 Washer, Flat, White 141402-2 Conn, Barrier GLTN, 2 Pos, Black 141405 Pivot, Satellite Enclosure, Black 182604-1 Pivot, Satellite Enclosure, White 141401-2 Twiddler™, Gasketed, 50mm, 184473 Shielded Grille Assy, Satellite, Black 175177-1...
  • Page 138 CD20 INSERT TAB INTO SLOT BETWEEN TOP OF DOOR AND TOP COVER CD20 Pack DUAL VOLTAGE UNITS ARE PACKED WITH A 120V AND 220V POWER PACK CD20 PACK 34 35 36 Breaks Into Two Pieces AM25P BASS BOX Satellite Assembly Pack SATELLITE ASSEMBLY PACK...

  • Page 139: Packing Part List

    PACKING PART LIST (see Figure 23. Packing) Item Part Description Note Number Number 177904-19 Sat Assy, Black 177904-29 Sat Assy, White 146999 Line Cord, 120V, US 134725 Line Cord, 230V, UK 148203 Line Cord, 230V, EU 134726 LIne Cord, 240V, AU 187719-001 Carton, LS25, US 187720...
  • Page 140 177870-B2 ® Powered Acoustimass 9 P (AM9P) Popping Sound Reason: The compressor circuit is causing a popping sound. Results: A customer may complain of a popping sound coming from the bass box when the unit is turned on or unmuted. Action: Perform the following procedure.
  • Page 141 Solder Side Layout...

  • Page 142: Service Bulletin

    Symptom: AM-25P intermittently will not turn on, even though the music center display is on. Reason: U604, optocoupler MOC3023T, is not compatible with circuit design. Solution: Replace U604 optocoupler MOC3023T Bose part number 190334-001 with optocoupler MOC3063T Bose part number 172297. AC IN M207 M107...
  • Page 143 "VIA" hole just below the "4" in the reference designator R643. 3. Change the value of R615 from: 9.1KΩ Bose part # 133626-9125 to: 14.0KΩ Bose part# 133625-1402 4. Change the value of R616 from: 2.00KΩ Bose part# 133625-2001 to: 4.02KΩ...
  • Page 144 Figure 2. 188574 PCB Component Side Layout...
  • Page 145 In this situation ports are incorrectly configured and serial data pulses from pin 13 cause rapid ON/OFF pulsing of Triac Q605 and blows the fuse. Solution: Install Voltage reset chip Bose part number 181016-10 in place of D603 as described in the procedure below. This IC (Dallas Semiconductor part number DS1233) properly resets the microcontroller when the 5.5 Volt supply drops below 4.375 Volts.
  • Page 146 Figure 1 Location of D603 Figure 2. Placement of Reset Chip Figure 3. Pin Out...
  • Page 147 SPECIFICATIONS AND FEATURES SUBJECT TO CHANGE WITHOUT NOTICE ® ® Bose Corporation The Mountain Framingham Massachusetts USA 01701 P/N 177870-S4 REV. 00 7/97 FOR TECHNICAL ASSISTANCE OR PART ORDERS, CALL 1-800-367-4008...
  • Page 148 133625-3010 Capacitors Reference Description Part Number Designator C113, 213 .39uF, BOX, 85, 50V, 5% 137127-394 C115, 215 .022uF, BOX, 85, 50V, 5% 137127-223 C301 .39uF, BOX, 85, 50V, 5% 137127-823 Supplement © 1997 Bose Corporation Part Number 177870-S5 REV00 10/97...
  • Page 149 177870-S4, 194381, and 194382. From Reference Designator Description Part Number U601 uC, SO-28, ST6225M6 190782 U601 uC, SO-28, ST6225M6 190333 Reference Designator Description Part Number U601 uC, SO-28, ST6225M6 193580-001 Supplement © 1998 Bose Corporation Part Number 177870-S6...
  • Page 150 258007 Q700 SOT, BPLR, P, 50V, 150MA 258007 Q701 SOT, BPLR, P, 50V, 150MA 258007 Q702 SOT, BPLR, P, 50V, 150MA 258007 Q703 SOT, BPLR, P, 50V, 150MA 258007 ECN: 30537 Supplement © 2002 Bose Corporation 5/2002 Part Number 177870-S7...

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