HCD-BX7, HCD-DX7, HCD-DX7J - Sony Audio Service Manual (repair manual)

1

HCD-BX7/DX7/DX7J is the tuner, deck, CD and
amplifier section in MHC-BX7/DX7/DX7J.

Model Name Using Similar Mechanism

NEW

CD Mechanism Type

CDM58-K2BD38

Base Unit Type

BU-K2BD38

Optical Pick-up Type

KSM-213DAP

Model Name Using Similar Mechanism

NEW

Tape Transport Mechanism Type

TCM-230MWR11

CD

SECTION

TAPE DECK

SECTION

Photo: HCD-DX7

US Model

Canadian Model

AEP Model

UK Model

HCD-BX7

E Model

HCD-DX7/DX7J

Australian Model

HCD-DX7

2003L02-1

© 2003.12

2

(US model only)

    After correcting the original service problem, perform the
following safety checks 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.

    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 microampers).
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 2V AC range are suitable. (See
Fig. A)

µ

Ω

3

This appliance is classified as a CLASS 1 LASER product. The
CLASS 1 LASER PRODUCT MARKING is located on the rear
exterior.

Laser component in this product is capable
of emitting radiation exceeding the limit for
Class 1.

CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation
exposure.

Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be

damaged by heat.

Flexible Circuit Board Repairing
• Keep the temperature of soldering iron around 270˚C

during repairing.

• Do not touch the soldering iron on the same conductor of the

circuit board (within 3 times).

• Be careful not to apply force on the conductor when soldering

or unsoldering.

The laser diode in the optical pick-up block may suffer electrostatic
break-down because of the potential difference generated by the
charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The flexible board is easily damaged and should be handled with
care.

The laser beam on this model is concentrated so as to be focused on
the disc reflective surface by the objective lens in the optical pick-
up block. Therefore, when checking the laser diode emission,
observe from more than 30 cm away from the objective lens.

— BACK PANEL —

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······························· 16

7-1.

Circuit Board Location ····················································· 21

7-2.

Block Diagrams ································································ 22

7-3.

Printed Wiring Board – BD Section – ······························ 24

7-4.

Schematic Diagram – BD Section – ································· 25

7-5.

Printed Wiring Board – Main Section – ··························· 26

7-6.

Schematic Diagram – Main (1/3) Section – ····················· 27

7-7.

Schematic Diagram – Main (2/3) Section – ····················· 28

7-8.

Schematic Diagram – Main (3/3) Section – ····················· 29

7-9.

Printed Wiring Board – Power AMP Section –
(BX7 model) ····································································· 30

7-10. Schematic Diagram – Power AMP Section –

(BX7 model) ····································································· 31

7-11. Printed Wiring Board – Power AMP Section –

(DX7, DX7J model) ························································· 32

7-12. Schematic Diagram – Power AMP Section –

(DX7, DX7J model) ························································· 33

7-13. Printed Wiring Board – Panel Section – ··························· 34
7-14. Schematic Diagram – Panel Section – ····························· 35
7-15. Printed Wiring Board  – Leaf SW Section – ···················· 36
7-16. Schematic Diagram – Leaf SW Section – ························ 37
7-17. Printed Wiring Board – Driver Section – ························· 38
7-18. Schematic Diagram – Driver Section – ···························· 39
7-19. Printed Wiring Board – Trans Section –

(BX7 model) ····································································· 40

7-20. Schematic Diagram – Trans Section –

(BX7 model) ····································································· 41

7-21. Printed Wiring Board – Trans Section –

(DX7, DX7J model) ························································· 42

7-22. Schematic Diagram – Trans Section –

(DX7, DX7J model) ························································· 43

7-23. IC Pin Function Description ············································· 44
7-24. IC Block Diagrams ··························································· 46

8-1.

Main Section ····································································· 49

8-2.

Panel Section ···································································· 50

8-3.

Main Board Section ·························································· 51

8-4.

Tape Mechanism Deck Section-1 ····································· 52

8-5.

Tape Mechanism Deck Section-2 ····································· 53

8-6.

CD Mechanism Section ···················································· 54

8-7.

Base unit Section ······························································ 55

······································· 56

• Abbreviation

CND : Canadian model
AUS

: Australian model

G

: German model

EA

: Saudi Arabia model

MY

: Malaysia model

SP

: Singapore model

TH

: Thai model

KR

: Korea model

MX

: Mexican model

AR

: Argentina model

E2

: Central and
  South AMERICA

E3

: Middle and Near East

AED, AEP, CIS, UK, G, AUS,
KR, MX, TH models

AR, E, EA, SP, TW, MY models

US, CND models

DX7J model

4-225-040-1s

4-225-040-2s

4-225-040-3s

4-228-592-3s

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