Sony CFD ZW755 - Portable CD / Cassette User manual

CFD-ZW755
SERVICE MANUAL
CD RADIO CASSETTE-CORDER
SPECIFICATIONS
US Model
CD
Model Name Using Similar Mechanism CFD-ZW750/ZW770
CD Machanism Type KSM-213CDM
Section Optical Pick-up Type KSS-213C
TC Model Name Using Similar Machanism NEW
Section Tape Transport Mechanism Type MF-ZW755-117
AUDIO POWER SPECIFICATIONS
POWER OUTPUT AND TOTAL HARMONIC DISTORTION
With 3.2-ohm loads, both channel driven from 150 - 6,300 Hz; rated 1.6
W per channel-minimum RMS power, with no more than
10 % total harmonic distortion in AC operation.
Other Specifications
CD player section
System
Compact disc digital audio system
Laser diode properties
Material: GaAlAs
Wave length: 780 nm
Emission duration: Continuous
Laser output: Less than 44.6 µW
(This output is the value measured at a distance of about 200
mm from the objective lens surface on the optical pick-up
block with 7 mm aperture.)
Spindle speed
200 r/min (rpm) to 500 r/min (rpm) (CLV)
Number of channels
2
Frequency response
20 - 20,000 Hz +1/–1 dB
Wow and flutter
Below measurable limit
Radio section
Frequency range
FM: 87.5 - 108 MHz
AM:530 - 1,710 kHz
Antennas
FM: Telescopic antenna
AM: Built-in ferrite bar antenna
Cassette-corder section
Recording system
4-track 2 channel stereo
Fast winding time
Approx. 120 s (sec.) with Sony cassette C-60
Frequency response
TYPE I (normal): 80 - 10,000 Hz
General
Speaker
Full range: 10 cm (4 in.) dia.,
3.2 ohms, cone type (2)
Outputs
Headphones jack (stereo minijack)
For 16 - 68 ohms impedance headphones
Power requirements
For CD radio cassette-corder:
120 V AC, 60 Hz
9 V DC, 6 size D (R20) batteries
For memory back-up:
4.5 V DC, 3 size AA (R6) batteries
For remote control:
3 V DC, 2 size AA (R6) batteries
– Continued on page 2 –
9-927-694-13
2004H02-1
© 2004.08
Sony Corporation
Personal Audio Company
Published by Sony Engineering Corporation
Ver 1.2 2004.08
With SUPPLEMENT-1

– 2 –
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK !OR DOTTED LINEWITH
MARK !ON THE SCHEMATIC DIAGRAMS AND INTHE PARTS
LIST ARE CRITICALTO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN
SUPPLEMENTS PUBLISHED BY SONY.
TABLE OF CONTENTS
Specifications ........................................................................... 1
1. SERVICING NOTES.................................................... 3
2. GENERAL....................................................................... 4
3. DISASSEMBLY
3-1. Cabinet (Rear) .......................................................... 6
3-2. Power Board, Back up Board, Battery Board........... 6
3-3. CD Block ASSY ....................................................... 7
3-4. Control Board ........................................................... 7
3-5. Power Key Board, Mega Bass Board,
Preset Board, Volume Board ..................................... 8
3-6. Key Board................................................................. 8
3-7. Headphone Board ..................................................... 8
3-8. REC SW Board, PB Board ....................................... 9
3-9. Mechanism Deck ...................................................... 9
3-10. Capstan/reel Motor (M301), Belt ........................... 10
3-11. Main Board ............................................................. 10
3-12. CD Board.................................................................11
3-13. Optical pick-up Block .............................................11
4. ADJUSTMENTS
4-1. Mechanical Adjustments........................................... 12
4-2. Electrical Adjustments .............................................. 12
5. DIAGRAMS
5-1. Explanation of IC Terminals..................................... 15
5-2. Block Diagrams ........................................................ 17
5-3. Schematic Diagram (Main Section) ......................... 21
5-4. Printed Wiring Boards (Main Section) ..................... 25
5-5. Printed Wiring Boards (Control Section) ................. 28
5-6. Schematic Diagram (Control Section)...................... 31
5-7. Printed Wiring Boards (CD Section) ........................ 34
5-8. Schematic Diagram (CD Section) ............................ 37
6. EXPLODED VIEWS
6-1. Rear Cabinet Section............................................... 44
6-2. Front Cabinet Section.............................................. 45
6-3. CD Section .............................................................. 46
6-4. Tape Mechanism Section-1 (MF-ZW755-117)....... 47
6-5. Tape Mechanism Section-2 (DECK A)
(MF-ZW755-117) ................................................... 48
6-6. Tape Mechanism Section-3 (DECK A)
(MF-ZW755-117) ................................................... 49
6-7. Tape Mechanism Section-4 (DECK B)
(MF-ZW755-117) ................................................... 50
6-8. Tape Mechanism Section-5 (DECK B)
(MF-ZW755-117) ................................................... 51
6-9. Optical pick-up Section (KSM-213CDM) .............. 52
6-10.Speaker Section ....................................................... 53
7. ELECTRICAL PARTS LIST.................................... 54
CAUTION
Use of controls or adjustments or performance
of procedures other than those specified herein
may result in hazardous radiation exposure.
Power consumption
AC 15 W
Battery lifeFor CD radio cassette-corder:
FM recording
Sony R20P: approx. 7.5 h
Sony alkaline LR20: approx. 22 h
Tape playback
Sony R20P: approx. 7 h
Sony alkaline LR20: approx. 20 h
CD playback
Sony R20P: approx. 3 h
Sony alkaline LR20: approx. 10 h
For memory back-up: approx. 1 year
Dimensions
Approx. 650 x 265 x 256 mm (w/h/d)
(25 5⁄8x 10 1⁄2x 10 1⁄8inches) (incl. projecting parts)
Mass Approx. 6.7 kg (14 lb. 12 oz) (incl. batteries)
Supplied accessory
AC power cord (1)
Remote control (1)
Design and specifications are subject to change without notice.
NOTES ON HANDLINGTHE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer electro-
static breakdown because of the potential difference generated
by the charged electrostatic load, etc. on clothing and the human
body.
During repair, pay attention to electrostatic breakdown 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.
NOTES ON LASER DIODE EMISSION CHECK
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 more than 30 cm away from the objective
lens.
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.
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.

– 3 –
CHUCK PLATE JIG ON REPAIRING
On repairing CD section, playing a disc without the CD lid, use
Chuck Plate Jig.
• Code number of Chuck Plate Jig : X-4918-255-1
SECTION 1
SERVICING NOTES
LASER DIODE AND FOCUS SEARCH OPERATION
CHECK
1. Turn on POWER button and press CD button to CD
position.
2. Open the CD lid.
3. Turn on S901 as following figure.
4. Confirm the laser diode emission while observing the
objecting lens. When there is no emission, Auto Power
Control circuit or Optical Pick-up is broken.
Objective lens moves up and down three for focus search.
SAFETY CHECK-OUT
After correcting the original service problem, perform the
following 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.
LEAKAGETEST
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 0.5mA (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
orbattery-operatedAC voltmeter.The“limit” indication is 0.75V,
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 2VAC range are suitable. (See Fig. A)
AC
voltmeter
(0.75V)
To Exposed Metal
Parts on Set
Earth Ground
0.15 µF 1.5kΩ
Fig. A. Using an AC voltmeter to check AC leakage.
Insert a precision
screw driver and push
SWITCH (S901)

– 4 –
SECTION 2
GENERAL This section is extracted from
instruction manual.
BasicOperations4
Playing a CD
BasicOperations
Tracknumber Playing time
3
With the label side up
Display
For hookup instructions, see pages 26 – 28.
1Push 6 PUSH OPEN/C OSE
down to open the CD
compartment and place the CD
on the CD compartment.
2Close the lid of the CD
compartment.
3Press ^.
The player turns on (direct
power-on) and plays all the tracks
once.
1,2
BasicOperations
BasicOperations
5
Use these buttons for additional operations
Tip
Next time you want to
listen to a CD, just press
^. The player turns on
automatically and starts
playing the CD.
To Do this
adjust the volume Turn VO UME (Press
VO +, – on the remote).
stop playback Press p.
pause playback Press ^ ( P on the
remote).
Press the button again to
resume play after pause.
go to the next track Turn PRESET•TIME SET
clockwise (Press + on
the remote).
go back to the previous track Turn PRESET•TIME SET
counterclockwise (Press
=on the remote).
remove the CD Press 6 PUSH OPEN/
C OSE.
turn on/off the player Press POWER.
POWER 6PUSHOPEN/CLOSE
VOLUME
^
p
PRESET
TIMESET
BasicOperations 6
Listening to the radio
For hookup instructions, see pages 26 – 28.
1Press RADIO BAND until the
band you want appears in the
display (direct power-on).
Each time you press the button,
the indication changes as follows:
"FM1" n "FM2" n "AM".
2Hold down TUNE + or – until the
frequency digits begin to change
in the display.
The player automatically scans
the radio frequencies and stops
when it finds a clear station.
If you cannot tune in to a station,
press the button repeatedly to
change the frequency step by
step.
Display
2
1
Indicates an FM stereo
broadcast
BasicOperations
BasicOperations
7
Use these buttons for additional operations
Tips
• The "FM1" and "FM2"
bands have the same
functions. You can store
the stations you want
separately in "FM1" and
"FM2".
• If the FM broadcast is
noisy, press MODE until
“Mono” appears in the
display and radio will
play in monaural.
• Next time you want to
listen to the radio, just
press RADIO BAND.
The player turns on
automatically and starts
playing the previous
station.
To Do this
adjust the volume Turn VO UME (Press
VO +, – on the remote).
turn on/off the radio Press POWER.
Toimprovebroadcastreception
Reorient the antenna for FM. Reorient the player itself
for AM.
for FM for AM
VOLUME
POWER MODE

–5 –
BasicOperations8
Playing a tape
For hookup instructions, see pages 26 – 28.
1Press p6 to open the tape
compartment and insert a
recorded tape. Use TYPE I
(normal) tape only. Close the
compartment.
2Press (.
The player turns on ( direct
power-on) and starts playing.
With the side you want
to play facing you
12 12
Display
BasicOperations
BasicOperations
9
Use these buttons for additional operations
To Do this
adjust the volume Turn VO UME (Press
VO +, – on the remote).
stop playback Press p6.
fast-forward or rewind the tape Press ) or 0.
pause playback Press P.
Press the button again to
resume play after pause.
eject the cassette Press p6.
turn on/off the player Press POWER.
Note
During playback, do not
press buttons on the
other deck. Otherwise
the playback speed may
change.
Tip
Next time you want to
listen to a tape, just
press (. The player
turns on automatically
and starts playing the
tape.
POWER
VOLUME
0, )
0, )
p6
P
p6
P
BasicOperations10
Recording on a tape
For hookup instructions, see pages 26 – 28.
1Press p6 to open the tape
compartment on deck B and
insert a blank tape. Use TYPE I
(normal) tape only.
2Select the program source you
want to record.
To record from the CD player:
insert a CD (see page 4) and press
CD.
To record from the radio:
tune in the station you want (see
page 6).
To record from the tape (dubbing):
insert a recorded tape into deck A
and press TAPE until “dUb”
appears in the display.
Display
With the side you want to
record on facing you
312
BasicOperations
BasicOperations
11
3Start recording.
To record from the CD player and
the radio, press r on deck B ((
is depressed automatically).
To record from the tape, press r
on deck B ((is depressed
automatically). Then press ( on
deck A.
DeckB
To Press
stop recording p6 on deck B
pause recording P on deck B
Press the button again to
resume recording.
turn on/off the player POWER
Use these buttons for additional operations
Tips
• Adjusting the volume or
the audio emphasis (see
page 25) will not affect
the recording level.
• For the best results, use
the AC power as a
power source.
• If the AM program
makes a whistling
sound after you've
pressed r in step 3,
press MODE repeatedly
until the noise at a
minimum.
POWER
p6
P
To erase a recording, proceed as follows:
1 Insert a tape whose recording you want to erase into deck
B.
2 Press TAPE untill “TAPE” appears in the display.
3 Press r on deck B.
DeckA
MODE

–6 –
SECTION 3
DISASSEMBLY
Note :Follow the disassembly procedure in the numerical order given.
3-1. CABINET (REAR)
3-2. POWER BOARD, BACK UP BOARD, BATTERY BOARD
zThe equipment can be removed using the following procedure.
Cabinet (Front)
sub ASSY
Power board, Back up board, Battery board
Cabinet (Rear)
Set CD block ASSY Power key board, Mega bass board,
Preset board, Volume board
Key board
Control board
Headphone board
Main board CD board Optical pick-up block
REC SW board, PB board Mechanism deck Ca
p
stan/reel motor
(
M301
)
, Belt
2Screws (BVTP 3x10)
63Screws (BVTP 3x14)
5Screw (BVTP 3x14)
4Screws
(
BVTP 3x14
)
1Handle
Cabinet (rear)
7CNP901
Cabinet (front) sub ASSY
POWER board
Back u
p
board
6Claw
Battery board
3Screws (BVTP 3x10)
8Bracket (2), Yok
e
1CN903
4Screws (BVTP 3x10)
Cabinet (rear)
2CN904
7
5
9

–7 –
3-3. CD BLOCK ASSY
3-4. CONTROL BOARD
2CN310
4
2CN305
2CN303
2CN311
3To S901
(CD door open/close)
CD block ASSY
2Wire, parallel
(23 core) (CN308)
2CN306
1Screws (BVTP 3x12)
1Screws (BVTP 3x12)
Cabinet (front) sub ASS
Y
2Screws (BVTP 2.6x8)
3
Control board
1CN80
8
2Screws (BVTP 2.6x8)
1CN806
1CN807
Cabinet (front) sub ASSY

–8 –
3-5. POWER KEY BOARD, MEGA BASS BOARD, PRESET BOARD,VOLUME BOARD
3-6. KEY BOARD 3-7. HEADPHONE BOARD
7Screw (BVTP 2.6x8)
qs Screw
(BVTP 2.6x8)
9
qf
2
4
6Nut and washer
5Knod, preset
1Screws (BVTP 2.6x8)
3Screws (BVTP 2.6x8)
8Claws
qd Claws
Cabinet (front) sub ASS
Y
Preset board
Mega bass board
Volume board
Power key board
qa Nut and washer
0Knod, volume
2
1Claws
1Claws
Key board
Control boar
d
2
1Bracket (2), yoke
Headphone board

–9 –
3-8. REC SW BOARD, PB BOARD
3-9. MECHANISM DECK
3Screw (BVTP 3x10)
4
7
2Remove solder
1CN304
6Screw
(BVTP 3x10)
REC SW board
PB board
WHT
BLK
RED
Shield
5Remove solder
WHT BLK
Shield
Cabinet (front) sub ASSY
1Screws (BVTP 3x10)
Mechanism dec
k
2
Cabinet (front) sub ASSY

–10 –
3-10. CAPSTAN/REEL MOTOR (M301), BELT
3-11. MAIN BOARD
DECK ASSY, A
DECK ASSY, B
3Belt 1Screws
(+PTT 2x5)
4Screws (M2.6x2.5)
25Capstan/reel
motor (M301
)
3Belt
1Screws (+PTT 2x5)
Chassis (sub)
1Screw (+PTT 2x5)
2Screws (BVTP 3x10)
31CNP704
2Screws (BVTP 3x10)
CD block ASSY
CD board
Main board

–11 –
3-12. CD BOARD
3-13. OPTICAL PICK-UP BLOCK
3Screws (BVTP 3x10)
1Wire, parallel
(16 core) (CN701
)
4
2CN702
3Screws (BVTP 3x10)
CD block ASSY
CD board
1Screws (+PWH 2.6x10)
1Screws (+PWH 2.6x10)
2
Optical pick-up block
Chassis, CD

– 12 –
PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab :record/playback head pinch roller
erase head rubber belt
capstan
2. Demagnetize the record/playback head with a head demagne-
tizer. (Do not bring the head demagnetizer close to the erase
head.)
Do not use a magnetized screwdriver for the adjustments.
3. These measurement adjustment should be performed with the
rated power supply voltage (9 V) unless otherwise noted.
Torque Measurement DECK A DECK B
Mode Torque Meter Meter Reading
Forward 22.5 to 55 g • cm
CQ-102C (0.32 to 0.76 oz• inch)
Forward 2 to 5 g • cm
back tension (0.03 – 0.069 oz• inch)
Fast Forward 60 to 120 g • cm
and CQ-201B
Rewind (0.84 – 1.66 oz• inch)
TapeTension Measurement DECK A DECK B
Mode Torque Meter Meter Reading
Forward CQ-403A more than 150 g
(more than 5.3 oz)
4-1. MECHANICAL ADJUSTMENTS
TAPE SECTION
Standard Output level
Outout terminal SP OUT PHONES OUT
load impedance 3.2 Ω32 Ω
output signal level 0.775V (0dB) 0.25V (–10dB)
TestTape
Type Signal Used for
WS-48A 3kHz, 0 dB Tape Speed Adjustment
Tape Speed Adjustment DECK A DECK B
Procedure :
1. Playback WS-48A (tape center part) and adjust RV301 so that
the frequency counter reading becomes 3,000Hz.
Standard value : 2,985–3,015Hz
2. Playback WS-48A(tape top and end).
Check that frequency counter reading is within 1.5% of the read-
ing of step 1.
Adjustment Location :
set
test tape
WS-48A
(3kHz, 0 dB) 32 Ω
digital frequenc
y
counter
PHONES jack (J301)
SECTION 4
ADJUSTMENTS
0 dB = 0.775V
[MAIN BOARD]
(Component side)
RV301 : Ta
p
e S
p
eed Ad
j
ustment
4-2. ELECTRICAL ADJUSTMENTS

–13 –
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1 450kHz
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust parts Frequency display Reading on digital
voltmeter
L4 530kHz Adjustment value : 0.8V
Standard value : 0.76 – 0.84V
Confirmation 1,710kHz Standard value : 4.4 – 5.2V
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L3 620kHz
CT2 1,400kHz
FM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T2 10.7MHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust parts Frequency display Reading on digital
voltmeter
Confirmation 87.5MHz Standard value : 1.5 – 2.1V
L2 108MHz Adjustment value : 4.2V
Standard value : 3.9 – 4.5V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1 87.5MHz
CT1 108MHz
TUNER SECTION
• FM Section
Setting :
RADIO BAND button : FM
• AM Section
Setting :
RADIO BAND button : AM
• Connecting Level Meter (FM and AM)
• Connecting DigitalVoltmeter (FM and AM)
AM RF signal
generator
30% amplitude modulation by 400Hz
signal.
Output level : as low as possible
Put the lead-wire
antenna close to
the set.
set
PHONES jack (J301)
32 Ω
level meter
(range : 0.5 – 5 V ac)
Adjustment Location : Main board (See page 14)
0 dB = 1µV• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
AM RF signal
generator
75 kHz frequency
deviation by 1 kHz signal
Output level : as low as possible
FH1
(antenna terminal)
set
(Main board)
0.01 µF
digital
voltmeter
VT
(JW13) 100K Ω

–14 –
Adjustment Location :
CD SECTION
CD section adjustments are done automatically in this set.
In case of operation check, confirm that focus bias.
Focus Bias Check
1. Connect the oscilloscope between IC701 ed pin (RFO) and ta
pin (VC) on CD board.
2. Insert the disc (YEDS-18). (Part No. : 3-702-101-01)
3. Press the ubutton.
4. Confirm that the oscilloscope waveform is as shown in the fig-
ure below. (eye pattern)
A good eye pattern means that the diamond shape (◊) in the cen-
ter of the waveform can be clearly distinguished.
• RF Signal Reference Waveform (eye pattern)
When observing the eye pattern, set the oscilloscope forAC range
and raise certical sensitivity
RF level
0.9 –1.5 Vp-p
VOLT/TV : 200mV (10 : 1 probe in use)
TIME/DIV : 500 nS
JW13
FH1
VT (JW13)
IC2
IC1
L2 : FM Frequency Coverage Adjustment
L4 : AM Frequency Coverage Adjustmen
t
CT2 : AM Tracking Adjustment
T2 : FM IF Adjustment
T1 : AM IF Adjustment
L3 : AM Tracking Adjustment
[MAIN BOARD] (Component side)
FM Tracking Adjustment CT1
L1
JW735 JW736
JW725
JW708
JW718
JW711
758
1
5
10
13
14
20
2627
30
35
39
40
45
50 52
IC701
C717
C707
C721
C724
C723
C712 C735
C731
C766
C739
C727
C709
R
R755
R710
R747
R726
R728
R72
6
R718
R703
R701
R702 R704
R706
R720
R721
R717
R733
R742
R745
R74
715
C706
oscilloscop
e
IC701 pin ed (RFO)
IC701 pin ta (VC)
Connection point :
[CD BOARD] (Conductor side)

– 15 –
Pin No. Pin name I/O Description
1 C-SCOR/R-CNT I CD SCOR input.
2 RMC I Sircs receiver input.
3 CD O CD function output.
4 C-MUT O CD block mute output.
5 C-SEN1 I CD SENSE-1 input.
6 C-SEN2 I CD SENSE-2 input.
7 C-SQCK O CD Sub-Q read clock output.
8 C-SQSO I CD Sub-Q data input.
9 C-RST O CD reset output.
10 C-CLK O CD serial clock output.
11 C-LAT O CD serial latch output.
12 C-DATA O CD serial data output.
13 PCON O System power control output.
14 TAPE A O DECKA select signal output.
15 TAPE B O DECK B select signal output.
16 DUB. O Dubbing ON signal output.
17 JOG A I Preset JOG switch input.
18 JOG B I Preset JOG switch input.
19 VOL A I Volume JOG switch input.
20 VOL B I Volume JOG switch input.
21 PORT OUT O Pull up voltage output.
22 TC1 I Deck Atape play switch input.
23 TC2 I Deck B tape play switch input.
24 – 26 KEY-1 – 3 I Key input.
27 VL I Battery Low detect input.
28 VH I Battery High detect input.
29 INT/SFT-CLK O Shift clock output.
–––––––––
30 RST I System reset input.
31 EXTL I Oscillation input (4.19 MHz).
32 XTAL O Oscillation output (4.19 MHz).
33 VSS — GND.
34 VL O LCD drive port ON/OFF output.
35 – 37 VLC-3 – 1 O LCD drive voltage terminal.
38 – 41 COM0 – 3 O LCD drive common output.
42 – 60 SEG0 – 18 O LCD drive segment output.
61 NC — Not used.
62 RADIO O Radio B+ ON output.
63 MOTOR O Motor B+ ON output.
64 M.B CTL O Mega bass ON/OFF output.
65 ISS O ISS swithing output.
66 B-MUTE O Tuner mute signal output
67 R-LATCH O Tuner latch output.
68 R-CLK O Tuner clock output.
69 V-DATA/R-DATA O Tuner data output/volume data output.
70 V-LATCH O Volume latch output.
71 V-CLOCK O Volume clock output.
72 VDD — Power supply pin (+5 V).
73 TX O Oscillation output (32.768 kHz).
74 TXE I Oscillation input (32.768 kHz).
75 NC — Not used (OPEN).
76 NC — Not used (OPEN).
77 A-MUT O Audio mute output.
78 REC I Tape record signal input.
79 C-DOR I CD door open/close switch input.
80 REGCK I Regulator check.
SECTION 5
DIAGRAMS
5-1. EXPLANATION OF ICTERMINALS
IC801 CXP83516-606Q (SYSTEM CONTROL)

–16 –
zCircuit Boards Location
CD MOTOR board
CD board
MAIN boar
d
KEY board
CONTROL board
BATTERY board
POWER board
BACK UP board
MEGA BASS board
VOLUME board
POWER KEY board
PRESET board
HEADPHONE board
PB board
REC SW board

– 17 – – 18 – – 20 –– 19 –
CFD-ZW755
5-2. BLOCK DIAGRAMS
• Signal path.
F: FM
f: AM
E: PB (DECK B)
a: REC (DECK B)
d: PB (DECK A)
J: CD

– 23 – – 24 –– 21 – – 22 –
CFD-ZW755 5-3. SCHEMATIC DIAGRAM (MAIN SECTION) zRefer to page 40 – 41 for IC Block Diagrams.
Note:
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in Ωand 1/4W or less unless otherwise
specified.
•f: internal component.
•1: fusible resistor.
Note: The components identified by mark 0or dotted
line with mark 0are critical for safety.
Replace only with part number specified.
•U: B+ Line.
•H: adjustment for repair.
• Power voltage is dc 9 V and fed with regulated dc power
supply from battery terminal.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM (RADIO SECTION),
TAPE PLAY (TAPE SECTION)
( ) : AM (RADIO SECTION),
REC (TAPE SECTION)
• Voltagesaretaken with aVOM(Inputimpedance10 MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
F: FM
f: AM
E: PB (DECK B)
a: REC (DECK B)
d: PB (DECK A)
J: CD
rWaveforms (MAIN SECTION)
1
IC2 wa
(X-OUT)
2
3
T301
Q301 C
ATT :1/10
VOLT/DIV : 1 V AC
TIME/DIV : 5 µsec
VOLT/DIV : 1 V AC
TIME/DIV : 5 µsec
247mVp-p
75kHz
31.4Vp-
p
19.45µsec
3.4Vp-p
19.45µsec
VOLT/DIV : 0.1 V AC
TIME/DIV : 20 µsec

– 25 – – 27 –– 26 –
5-4. PRINTEDWIRING BOARDS (MAIN SECTION) zRefer to page 16 Circuit Boards Location.
Note:
•X: parts extracted from the component side.
•f: internal component.
•b: Pattern from the side which enables seeing.
D1 D-2
D2 D-3
D3 E-4
D4 G-2
D5 G-2
D301 C10
D302 D-8
D303 D-8
D321 F-4
D322 F-5
D323 F-5
D324 F-4
D325 I-6
D326 H-5
D328 F-4
D330 C-8
D331 I-5
D333 G-7
D334 D-7
D335 D-6
D349 C-9
D350 E-9
D352 C-8
D354 D-6
D355 D-6
D356 C-6
D357 D-6
D901 H-12
D902 H-12
D903 G-13
D904 G-13
D906 H-14
D907 G-14
D908 G-14
IC1 C-3
IC2 C-4
IC301 C-11
IC302 F-6
IC304 H-7
IC305 C-7
Ref.No. Location
zSemiconductor Location
Ref. No. Location
Q1 D-4
Q101 G-8
Q102 F-8
Q103 C-16
Q104 C-16
Q201 G-8
Q202 F-8
Q203 C-16
Q204 B-15
Q301 C-12
Q308 C-8
Q310 B-12
Q311 D-5
Q312 D-5
Q313 F-5
Q314 E-5
Q330 F-5
Q331 H-6
Q333 H-5
Q336 C-7
Q337 D-7
Q338 G-6
Q339 F-5
Q340 D-8
Q350 C-8
Q353 C-8
Q354 D-8
Q355 D-7
Q356 D-6
Q357 E-7
CFD-ZW755
C35
C51
C38
C10
C17
C13
C9
C31
C20
C11
C45
C46 C44
C47
C41
C40
C60
C59
C58
C57
C49
C6
C1
C29
C8
C21
C7
C4 C5
C2
C3
C30
C25
C26C28
C37
C22
C372
C152
C153 C154
C346
C328
C310
C309
C308
C203
C205
C105
C101
C103
C104
C107 C307
C306
C305
C311
C114
C119 C219
C214
C111
C211
C204
C201
C207
C907
C901
C904
C906
C902
C903
C312
C377
C156
C256
C253
C252
C237
C225 C227
C232
C132
C137
C127
C336
C343 C335
C342
C125
C254
C370
C371
C24
C331
C352
C27
C332
C15
C12
C48
C50
C34
R14
R20
R19
R7
R28
R29
R30
R10
R26
R39
R33
R32
R38
R6
R366
R377
R378
R152
R352
R351
R350
R388
R369
R372
R373
R207
C270
R260
C170
R160
R214
R215
R252
R218
R217
R206
R210
R116
R216
R390
R376 R371
R370 R389
R110
R106
R387
R254
R256
R156
R250
R107
R154
R155
R150 R118
R115 R117
R336
R335
R333
R365
R332 R334
R358
R328
R329
R259
R356
R159
R357
R362
R102
R305
R202
R309
R303
R304
R103
R101
R204
R203
R219
R208
R112
R201
R108
R129
R229
R104
R301
R306
R315
R212
R308
R228
R225
R122
R221
R121
R126
R133
R231
R233
R223
R124
R227
R222
R131
R224
R123
R125
R128
R127
R226
R310
R355
R331
R330
R380
R344
R343
R382
R381
R114
R255
R4
R3
R1
R8
R5
R9
R25
R2
R12
R15
R16
R17
R18
R11
JW5
JW320
JW16
JW347
JW346
JW354
JW345
JW344
JW343
JW330
JW18
JW349
JW6
JW23
JW13
JW24
JW10
JW8
JW11
JW12
JW15
JW16
JW348
JW6
JW25
JW3
JW354
JW353
JW352
JW361
JW360
JW356
JW358
JW365
JW356
JW363
JW364
JW351
JW355
JW355
JW303
JW306
JW302
JW301
JW304
JW302
JW357
JW366
JW342
JW340
JW339
JW341
JW1
JW2
JW7
JW21
JW328 JW329
JW331
JW326
JW314
JW311
JW310
JW315 JW318
JW321
JW332
JW333
JW334
JW322
JW323
JW320
JW335
JW336
JW337 JW338
JW319
JW317
JW316
JW312
JW313
JW325
JW327
JW22
JW20
JW26
JW4
R394
C32
C33 C53
C36
C42
C54
C14 C16
C43
C345 C303
C302
C106
C301
C102
C215
C212
C115 C213
C113
C116
C112
C217
C117
C216
C206
C304
C202
C378
C250C150C160C159
C158
C155
C157
C151
C257
C260
C259
C258
C255
C251
C374
C317
C330
C333
C341
C334
C344 C337
C135 C235 C326
C226 C126
C351
C136
C236
C348
C52
CT2
CT1
D1 D2
D3
L4
T2
T1 CF3 CF1 X1
IC1
IC2
IC305
1
1
22
20
15
12
5
10
11
510 12
13
15
2024
15 CN311
1
10
15
20
23
22 2
5
CN308
B
CONTROL BOARD
CNJ801
(Page 30)
A
CONTROL BOARD
CN803
(Page 29)
D
CD BOARD
CN704
(Page 35)
L1 L2
L6
B
C
E
Q1
B
C
E
Q312
E
C
B
Q311
B C E
Q356
B C E
Q355
B C E
Q337
B C E
Q353
E C B
Q336
E C B
Q340
E C B
Q357
E C B Q308
E C B Q350
E C B
Q354
123
L302
RV301
B
C
E
Q102
B
C
E
Q101
E
C
BQ202
B C E
Q201
L301
L101
L201
BCE
Q333
BCE
Q331
B
C
E
Q338
B
C
E
Q330
B
C
E
Q313
E
C
B
Q339
D356
D357
D334
D352 D349
D301
D302
D303
D330
D355 D354
D335
D350
D322
D328
D324
D321
D5
D4
D326
D333
D902
D907
D906
D901
D903 D904
D323
D325
D331
51011141
1
5
8
1
1
1
6
1
5
51015
5
CN303
CN305
CN306
CN304
CN301
CNJ304
CN306
CN310
CNJ309
CNJ307
510111
4
41
1
S306
(MD POWER)
DECK B
S307
(MD PLAY)
S304
(MD POWER)
DECK A
S305
(MD PLAY)
M
M301
CAPSTAN/REEL
MOTOR
15 CNJ310
IC302
IC304
1 5 10 15
16
20
25
30
14
1
5
CN901
CN902
CN904
SP902
SPEAKER
(R-CH)
SP901
SPEAKER
(L-CH)
+
–
+
–
L
R
+ +
–
–
J302
SPEAKER IMPEDANCE 3.2Ω
ANT1
FM
TELESCOPIC ANTENNA
L3
AM
FERRITE-ROD
ANTENNA
IC301
1
5
10
12
13
15
20
24
1
4
L-CH
R-CH
HRP301
RECORD/ PLAYBACK
HEAD
(DECK B)
HE301
ERASE HEAD
(DECK B)
HP301
PLAYBACK
HEAD
(DECK A)
T301
S301
REC
T
PB
E C B
Q204
E
C
BQ104
E
C
B
Q103
B C E Q203
J301
PHONES
T901
POWER TRANSFORMER
F901
JW904
JW913 JW911
D908
CN903
RED
RED
RED
RED RED
J901
-
AC IN
DRY BATTERY
SIZE "AA"
(IEC DESIGNATION R6)
3PCS, 4.5V
(FOR CLOCK BACK UP)
DRY BATTERY
SIZE "D"
(IEC DESIGNATION R20)
6PCS, 9V
JW901
JW902
[BACK UP BOARD]
11
(11)
1-677-742-
[POWER BOARD]
11
(11)
1-677-753-
[HEADPHONE BOARD]
11
(11)
1-677-744-
11
(11)
1-677-740-
[PB BOARD]
[BATT BOARD]
[REC SW BOARD]
[MAIN BOARD]
11
(11)
1-677-743-
11
(11)
1-677-748-
11
(11)
1-677-741-
23 4 5 6 7 89 10 11 12 13 14 15 16 17
A
1
B
C
D
E
F
G
H
J
I
02
L5
E C B
Q314
R119
B C E
Q310
B
C
E
Q301
(CHASSIS)
1
2
1
3
2
1
CN302
FH1

02
C850
C817
C814
C844
C804
C815
C803
C834
C833
C810
C824
C826
C840 C835
C823
C825
C830
C842
C829
C827
C828
C802
C801
C805
C843
C838
C839
C813
C812
C816
C820
C836
C837
JW805
JW803
JW824
JW814
JW817
JW802
JW818
JW804
JW808
JW819
JW809
JW828
JW807
JW813
JW829
JW827
JW812
JW833
JW834
JW830
JW826
JW825
JW823
JW820
JW801
JW816
JW822
JW811
JW835
JW815
JW810
JW831
JW821
JW806
JW832
R828
R831
R835
R836
R851
R833
R834
R848
R840
R866 R839
R861
R858R850
R852 R868
R864
R842
R844
R853
R865
R843
R847
R845
R841
R875
R811
R884
R803
R804
R805
R855
R846
R867
R860
R837
R838
R857
R849
R854
R883
R885
R802
R859
R882
R869
R872
R870
R801
R816
R807
R806
R810 R814
R863
R862
R873
R808
R809
R886
R856
R830
R832
R829
R819
R818
R813
R812
R815
R825
R817
R824 R823 R822 R821 R820
R827
R826 C811
C841
C831
S802
CD
D802
OPR/BATT
S801
POWER
S804
RADIO
BAND
S803
TAPE
S810
SOUND MODE
S811
TIMER
R876
S812
SLEEP
R877
S813
STANDBY
R878 R879
S814
CLOCK
S816
MODE
S815
DSPL
ENT
MEM
S808
MEGA BASS
S807
u
S809
x
S805
m
TUNE–
S806
M
TUNE+
X801
X802
B C E
Q802
B C E
Q801
1
5
10
15
20
24
25
30
35
40 41 45 50 55 60 64
65
70
75
80
IC801
IC803
1
1 5 10 15 20 23
1 3
2
5
9
10
1
1
2
5
1
3
2
5
10
15
20 22
23
CN802
CN803
L802
L801
CNJ801
CN804
LCD801
LIQUID CRYSTAL DISPLAY
CNJ806
CN808
CN808
CN806
CNJ807
C
CD BOARD
CN703
(Page 36)
A
MAIN BOARD
CN308
(Page 25)
B
MAIN BOARD
CN311
(Page 25)
1
2
3
CN807
1
2
1
2
3
CN806
1 2 3
CNJ804
2
1
CNJ806
S901
CD DOOR
OPEN/CLOSE
D801
13
12
2
1
VR802
VOLUME
+
–
VR801
PRESET
TIME SET
11
(11)
1-677-751-
11
(11)
1-677-750-
11
(11)
1-677-747-
11
(11)
1-677-745-
11
(11)
1-677-749-
[POWER KEY BOARD]
[PRESET BOARD] [VOLOME BOARD]
[MEGA BASS BOARD]
[KEY BOARD]
[CONTROL BOARD]
\ .>
X
11
(11)
1-677-746-
23 4 5 6 7 89 10 11 12
A
1
B
C
D
E
F
G
H
IC802
1
4
1
4
– 28 – – 30 –– 29 –
CFD-ZW755
5-5. PRINTEDWIRING BOARDS (CONTROL SECTION) zRefer to page 16 Circuit Boards Location.
Note:
•X: parts extracted from the component side.
•b: Pattern from the side which enables seeing.
Ref.No. Location
zSemiconductor
Location
D801 D-9
D802 E-6
IC801 D-7
IC802 F-5
IC803 H-11
Q801 E-6
Q802 E-5
rWaveforms (CONTROL SECTION)
1
IC801 es
(XTAL)
2
VOLT/DIV : 1 V AC
TIME/DIV : 50nsec
IC801 ud
(TX) VOLT/DIV : 1 V AC
TIME/DIV : 10µsec
2.98Vp-
p
4.19MHz
4.8Vp-p
32kHz
Note on Schematic Diagram: Control Section
Note:
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in Ωand 1/4W or less unless otherwise
specified.
•U: B+ Line.
• Power voltage is dc 9 V and fed with regulated dc power
supply from battery terminal.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
• Voltagesare taken withaVOM(Input impedance 10MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
• Circled numbers refer to waveforms.