Sony HCD-BX20I - Compact Disc Receiver Component, Service Manual

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HCD-BX20i/BX50BTi
3
1. SERVICING NOTES
............................................. 4
2. GENERAL
.................................................................. 6
3. DISASSEMBLY
3-1. Disassembly Flow ........................................................... 10
3-2. Panel (Side L/R) .............................................................. 11
3-3. Top Panel Block .............................................................. 11
3-4. TOP KEY Board, IP Board, Panel Top (IP) .................... 12
3-5. Front Panel Block ........................................................... 12
3-6. Rear Panel Block ............................................................ 13
3-7. Panel
(Rear) .................................................................... 13
3-8. AMP Board Block ........................................................... 14
3-9. POWER Board Block ..................................................... 14
3-10. MAIN Board ................................................................... 15
3-11. Loading Mechanism Block ............................................. 15
3-12. Base Unit ......................................................................... 16
3-13. Belt .................................................................................. 16
3-14. OP Base Assy (KSM-213D) ........................................... 17
4. TEST MODE
............................................................ 18
5. ELECTRICAL CHECKS
...................................... 20
6. DIAGRAMS
6-1. Block Diagram - CD SERVO Section - .......................... 21
6-2. Block
Diagram
- iPod, TUNER, BLUETOOTH Section - ...................... 22
6-3. Block Diagram - MAIN Section - ................................... 23
6-4. Block
Diagram
- PANEL, POWER SUPPLY Section - ........................... 24
6-5. Printed Wiring Boards - CD Section - ............................ 26
6-6. Schematic Diagram - CD Board - ................................... 27
6-7. Printed Wiring Boards - BLUETOOTH Section - .......... 28
6-8. Schematic Diagram - BLUETOOTH Section - .............. 29
6-9. Printed Wiring Board - IP Board - .................................. 30
6-10. Schematic Diagram - IP Board - ..................................... 31
6-11. Printed Wiring Boards - MAIN Section - ....................... 32
6-12. Schematic Diagram - MAIN Section (1/3) - ................... 33
6-13. Schematic Diagram - MAIN Section (2/3) - ................... 34
6-14. Schematic Diagram - MAIN Section (3/3) - ................... 35
6-15. Printed Wiring Boards
- HEADPHONE/AMP Section - ..................................... 36
6-16. Schematic Diagram - HEADPHONE/AMP Section - .... 37
6-17. Printed Wiring Boards - PANEL Section - ..................... 38
6-18. Schematic Diagram - PANEL Section - .......................... 39
6-19. Printed Wiring Board - POWER Board - ........................ 40
6-20. Schematic Diagram - POWER Board - .......................... 41
7. EXPLODED VIEWS
7-1. Panel Section ................................................................... 50
7-2. Top Panel Section ........................................................... 51
7-3. Front Panel Section ......................................................... 52
7-4. MAIN Board Section ...................................................... 53
7-5. POWER Board Section ................................................... 54
7-6. Loading Mechanism Section .......................................... 55
7-7. Base Unit Section (BU-K6BD90-WOD) ....................... 56
8. ELECTRICAL PARTS LIST
.............................. 57
TABLE OF CONTENTS SAFETY CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety check before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs,
screws, and all other exposed metal parts for AC leakage.
Check leakage as described below.
LEAKAGE TEST
The AC leakage from any exposed metal part to earth ground and
from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microamperes.).
Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturers’ instructions to use these
instruments.
2. A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a
VOM or battery-operated AC voltmeter. The “limit” indication
is 0.75 V, so analog meters must have an accurate low-voltage
scale. The Simpson 250 and Sanwa SH-63Trd are examples
of a passive VOM that is suitable. Nearly all battery operated
digital multimeters that have a 2 V AC range are suitable. (See
Fig. A)
Fig. A. Using an AC voltmeter to check AC leakage.
1.5 k Ω 0.15 μ F
AC
voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Earth Ground