DXA-WZ7AV, MHC-WZ7AV - Sony Audio Service Manual (repair manual)

E Model

• DXA-WZ7AV is deck and amplifier

section in MHC-WZ7AV.

The following measured at AC 127, 220, 240 V, 
50/60 Hz (Saudi Arabian model only)
The following measured at AC 220 V, 50/60 Hz 
(Thai model only)
The following measured at AC 120, 220, 240 V, 
50/60 Hz (except for Saudi Arabian and Thai models)

DIN power output (rated): 100 + 100 watts (6 ohms at 

1 kHz, DIN)

Continuous RMS power output (reference):

140 + 140 watts (6 ohms at 
1 kHz, 10% THD)

Continuous RMS power output (reference):

40 watts (6 ohms at 1 kHz, 
10% THD)

Continuous RMS power output (reference):

40 + 40 watts (6 ohms at 
1 kHz, 10% THD)

Inputs
MIC 1/2 (phone jacks):

sensitivity 1 mV, 
impedance 10 kilohms

MD (VIDEO) IN L/R (phono jacks):

sensitivity 450 mV 
(250 mV), impedance 
47 kilohms

DVD INPUT
FRONT, REAR, CENTER, WOOFER (phono jacks):

sensitivity 450 mV, 
impedance 47 kilohms

Outputs
MD (VIDEO) OUT L/R (phono jacks):

Voltage 250 mV, 
impedance 1 kilohms

SUB WOOFER OUT:

Voltage 350 mV, 
impedance 1 kilohms

VIDEO OUT (phono jacks):

max. output level
1 Vp-p, unbalanced, Sync 
negative, load impedance 
75 ohms

PHONES (stereo mini jack):

accepts headphones of 
8 ohms or more

FRONT L/R:

Use only the supplied 
speaker SS-WZ8

SURROUND L/R:

Use only the supplied 
speaker SS-RS400

CENTER:

Use only the supplied 
speaker SS-CT400

Recording system

4-track 2-channel, stereo

Frequency response

50 – 13,000 Hz (

±3 dB), 

using Sony TYPE I 
cassettes

Power requirements
Saudi Arabian model:

120 – 127 V, 220 V or 
230 – 240 V AC, 50/60 Hz
Adjustable with voltage 
selector

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

250 watts

Dimensions (w/h/d)
Amplifier/Tape deck:

Approx. 255 

× 135 ×

330 mm

Mass
Amplifier/Tape deck:

Approx. 7.7 kg

Design and specifications are subject to change 
without notice.

2003F1678-1

© 2003.06

Tape deck

Section

Model Name Using Similar Mechanism

DXA-WZ5

Tape Transport Mechanism Type

CWM43RR23

2

0

0

·········································································· 3

························································· 5

2-1. Case ··············································································· 5
2-2. Switching Power, DC Fan (FAN301) ···························· 6
2-3. TC MAIN Board ··························································· 6
2-4. FRONT AMP Board, SURROUND AMP Board ·········· 7
2-5. Front (TC) Panel Assy ··················································· 7
2-6. Tape mechanism deck (CWM43RR23) ························ 8
2-7. Lid (TC) Assy, Holder (A) Assy, Holder (B) Assy ········ 8

································· 9

······································································ 10

4-1. Block Diagrams ··························································· 11
4-2. Printed Wiring Board – TC MAIN Board – ················ 12
4-3. Schematic Diagram – TC MAIN Board (1/2) – ·········· 13
4-4. Schematic Diagram – TC MAIN Board (2/2) – ·········· 14
4-5. Printed Wiring Board – FRONT AMP Board – ·········· 15
4-6. Schematic Diagram – FRONT AMP Board – ············· 16
4-7. Printed Wiring Board – SURROUND AMP Board – · 17
4-8. Schematic Diagram – SURROUND AMP Board – ···· 18

5-1. Front Panel Section ····················································· 19
5-2. Chassis Section ···························································· 20
5-3. Tape Mechanism Deck Section (CWM43RR23) ········ 21

······································· 22

In case of repairing, please bring the entire system set([HCD-
WZ7AV, DXA-WZ7AV],except for the speaker) to the service
station.

• 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.

Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size.)

Unleaded solder has the following characteristics.
• Unleaded solder melts at a temperature about 40

°C higher than

ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350

°C.

Caution: The printed pattern (copper foil) may peel away if the
heated tip is applied for too long, so be careful!

• Strong viscosity

Unleaded solder is more viscous (sticky, less prone to flow) than
ordinary solder so use caution not to let solder bridges occur such
as on IC pins, etc.

• Usable with ordinary solder

It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.

— BACK PANEL —

PARTS No.

Saudi Arabian model

Thai model

Singapore model

4-244-468-4

s

4-244-468-5

s

4-244-468-6

s

3

This section is extracted
from instruction manual.

Deck A wl
Deck B wh

A Z (eject) wk
Z B (eject) wj

Amplifier/Tape deck

wl

wh

wkwj

ALBUM +/– 6 (12, 16)
CD wa (11, 14, 16, 22, 23, 28)
CENTER LEVEL +/– qa (9)
CLEAR ed (16, 17)
CLOCK/TIMER SELECT t;

(29, 30)

CLOCK/TIMER SET rl (10, 28, 

29)

DIMMER 5 (31)
DISPLAY 4 (30, 31)
DVD eh (36)
EFFECT ra (24, 25, 27)
ENTER r; (10, 16, 18, 25, 28, 

29)

EQ EDIT rs (25)
FM MODE wj (20)
GROOVE qh (24, 27)
KARAOKE/MPX rh (26)
KEY CONTROL 

#

/

2

qd (27)

MD (VIDEO) rd (35)
MOVIE MODE qk (24, 27)
MUSIC MODE qj (24, 25, 27)
NEXT rg (13, 14, 17)
Number buttons wf (14, 17)
ON SCREEN wh (32)

PLAY MODE/DIRECTION rk

(12, 16, 21, 22, 23, 27)

PRESET –/+ ws (18, 19)
PREV rf (13, 14, 17)
PROGRAM EDIT ek (22)
PRO LOGIC qf (9, 26)
REPEAT wk (15)
SELECT wd
SLEEP wl (28)
SPECIAL MENU wg (17)
SURROUND ql (25)
SURROUND LEVEL +/– q; (9)
TAPE A/B ej (21, 22, 23, 27, 28)
TEST TONE el (9)
TUNER/BAND 9 (18, 19, 20, 

23, 28)

TUNER MEMORY es (18)
TUNING –/+ eg (18, 20)
TUNING MODE rj (18, 19)
TV CH +/– 3 (35)
TV VOL +/– 2 (35)
TV/VIDEO ea (35)
VOL +/– qs (9, 28)
2CH/MULTI w; (36)

?/1 (power) 1 (7, 28)
m/M (rewind/fast forward) 

eg (12, 18, 21)

./> (go back/go forward) 

ws (12, 18, 21)

nN (play) wd (12, 21, 22, 27)
X (pause) 7 (12, 21)
x (stop) 8 (12, 21, 22, 27)

M

/m/</, (cursor) qg (9, 28)

TV ?/1 e; (35)
RETURN O ef (14)

–

–

M

x

+

+

–

–

+

+

–

+

O

.

>

m

b

B

V

v

nN

X

+
–

wl

wa

w;

ql

qf

qg

qh

qs

qa

qd

1

3

2

wf

qj

qk

ws

wd

4

5

6

7

8

9

q;

wk

wj

wh

wg

–

–

M

x

+

+

–

–

+

+

–

+

O

.

>

m

b

B

V

v

nN

X

+
–

t;

rl

rk

rf

r;

ra

rs

el

ef

ed

es

ea

e;

eg

eh

ek

ej

rh

rd

rg

rj

4

Perform the following procedures 1 to 7 to hook up your system using the supplied cords and 
accessories. Middle Eastern model is used for illustration purpose.

Place the components as shown below.

1

Connect to the same numbered jack in the 
order indicated on the rear panel.

The system cable is used to send signals and electricity 
between the components for interlinked operation.
Be sure to insert the connector horizontally until it 
clicks into place. Otherwise the system will not operate 
correctly.

2

Connect the appropriate speaker cords from 
the speaker terminals to the corresponding 
SPEAKER terminals on the amplifier.

AM loop antenna

FM lead antenna

CD player/Tuner

Amplifier/Tape deck

To front speaker (right)

To front speaker 
(left)

To surround speaker (right)

To surround speaker (left)

To center speaker

Amplifier/
Tape deck

CD player/
Tuner