MHC-VX33 (serv.man2) - Sony Audio Service Manual (repair manual)

E Model

Tourist Model

— Continued on next page —

• HCD-VX33 is the tuner, deck, CD

and amplifier section in MHC-
VX33.

Model Name Using Similar Mechanism

NEW

CD

CD Mechanism Type

CDM58-K2BD37A

Section

Base Unit Name

BU-K2BD37A

Optical Pick-up Name

KSM-213D

Tape deck

Model Name Using Similar Mechanism

NEW

Section

Tape Transport Mechanism Type

TCM-230PWR11

MHC-VX33:
The following measured at AC 120, 220, 240 V
50/60 Hz
DIN power output (rated) 75 + 75 watts

(6 ohms at 1 kHz, DIN)

Continuous RMS power output (reference)

100 + 100 watts
(6 ohms at 1 kHz,
10% THD)

Inputs
MD/VIDEO IN:

voltage 450/250 mV,

(phono jacks)

impedance 47 kilohms

MIC:

sensitivity 1 mV,

(mini jack)

impedance 10 kilohms

Outputs
VIDEO OUT:

max. output level

(phono jack)

1Vp-p, unbalanced, Sync
negative, load impedance
75 ohms

S-VIDEO  OUT:

Y: 1Vp-p, unbalanced,

(4-pin/mini-DIN jack)

Sync negative,
C: 0.286Vp-p,
load impedance 75 ohms

PHONES:

accepts headphones of

(stereo mini jack)

8 ohms or more

SPEAKER:
MHC-VX33:

accepts impedance of 6 to
16 ohms

System

Compact disc and digital
audio system

Laser

Semiconductor laser
(

λ=780 nm)

Emission duration:
continuous

Laser output

Max. 44.6 

µ   

W*

*This output is the value
measured at a distance of
200 mm from the
objective lens surface on
the Optical Pick-up Block
with 7 mm aperture.

Wavelength

780 – 790 nm

Frequency response

2 Hz – 20 kHz (

±0.5 dB)

Signal-to-noise ratio

More than 90 dB

Dynamic range

More than 90 dB

Video color system format

NTSC, PAL

CD OPTICAL DIGITAL OUT
(Square optical connector jack, rear panel)
Wavelength

660 nm

Output Level

–18 dBm 

2003K16-1

© 2003.11

2

0

0

1.

Check the area of your repair for unsoldered or poorly-soldered
connections.  Check the entire board surface for solder splashes
and bridges.

2.

Check the interboard wiring to ensure that no wires are
"pinched" or contact high-wattage resistors.

3.

Look for unauthorized replacement parts, particularly
transistors, that were installed during a previous repair.  Point
them out to the customer and recommend their replacement.

4.

Look for parts which, through functioning, show obvious signs
of deterioration.  Point them out to the customer and
recommend their replacement.

After correcting the original service problem, perform the following safety
checks before releasing the set to the customer.

5.

Check the B+ voltage to see it is at the values specified.

6.

Flexible Circuit Board Repairing

• Keep the temperature of the 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.

Power requirements
Thai model:

220 V AC, 50/60 Hz

Other models:

120 V, 220 V or
230 — 240 V AC, 50/60 Hz
Adjustable with voltage
selector

Power consumption

190 watts

Dimensions (w/h/d)

Approx. 280 x 325 x 403 mm

Mass

Approx. 8.9 kg

Supplied accessories:

AM loop antenna (1)
FM lead antenna (1)
Remote Commander (1)
Batteries (2)
Video cable (1)
Front speaker pads (8)

Design and specifications are subject to change
without notice.

Recording system

4-track 2-channel stereo

Frequency response

40 — 13,000 Hz (

±

3 dB),

using Sony TYPE I
cassette

FM stereo, FM/AM superheterodyne tuner

Tuning range
Tourist model:

76.0 — 108.0 MHz

Other models:

87.5 — 108.0 MHz

Antenna

FM lead antenna

Antenna terminals

75 ohm unbalanced

Intermediate frequency

10.7 MHz

Tuning range
Middle Eastern model:

531 — 1,602 kHz
(with the interval set at
9 kHz)

Other models:

531 — 1,602 kHz
(with the interval set at
9 kHz)
530 — 1,710 kHz 
(with the interval set at
10 kHz)

Antenna

AM loop antenna

Antenna terminals

External antenna terminal

Intermediate frequency

450 kHz

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.

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

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

damaged by heat.

• 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.

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7-1. Circuit Board Location ················································· 23
7-2. Block Diagrams ···························································· 25
7-3. Printed Wiring Board    BD Section ····························· 28
7-4. Schematic Diagram    BD Section ································ 29
7-5. Printed Wiring Board    Main Section ·························· 30
7-6. Schematic Diagram    Main Section (1/3) ···················· 31
7-7. Schematic Diagram    Main Section (2/3) ···················· 32
7-8. Schematic Diagram    Main Section (3/3) ···················· 33
7-9. Printed Wiring Board    Power AMP Section ··············· 34
7-10. Schematic Diagram    Power AMP Section ················ 35
7-11. Printed Wiring Board    Panel Section ························ 36
7-12. Schematic Diagram    Panel Section ··························· 37
7-13. Printed Wiring Board    Leaf SW Section ··················· 38
7-14. Schematic Diagram    Leaf SW Section ····················· 39
7-15. Printed Wiring Board    Driver Section ······················· 40
7-16. Schematic Diagram    Driver Section ························· 41
7-17. Printed Wiring Board    Video CD Section ················· 42
7-18. Schematic Diagram    Video CD Section (1/2) ··········· 43
7-19. Schematic Diagram    Video CD Section (2/2) ··········· 44
7-20. Printed Wiring Board    Power Section ······················· 45
7-21. Schematic Diagram    Power Section ·························· 45
7-22. IC Pin Function Description ······································· 46
7-23. IC Block Diagrams ····················································· 50

8-1. Main Section ································································· 54
8-2. Panel Section ································································ 55
8-3. Main Board Section ······················································ 56
8-4. Tape Mechanism Section (TCM-230PWR11) (1/2) ····· 57
8-5. Tape Mechanism Section (TCM-230PWR11) (2/2) ····· 58
8-6. CD Mechanism Section (CDM58-K2BD37) ··············· 59

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4

— BACK PANEL —

E, EA, HK, MY, SP, TW, JE models

TH model

IA model

4-224-547-3

s

4-224-547-5

s

4-226-245-4

s

• Abbreviation

EA

:Saudi Arabia model

MY

:Malaysia model

SP

:Singapore model

TH

:Thai model

TW

:Taiwan model

IA

:Indonesia model

HK

:Hong Kong model

JE

:Tourist model

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