Aiwa CX-JDS20 User manual

SERVICE MANUAL
Sony Corporation
Personal Audio Group
Published by Sony Engineering Corporation
AEP Model
CX-JDS20
E Model
CX-JDS20/JDS50
Australian Model
CX-JDS20
Russian Model
CX-JDS20/JDS50
COMPACT DISC DECK RECEIVER
9-879-515-01
2005C1678-1
© 2005.03
Ver. 1.0 2005.03
SPECIFICATIONS
CX-JDS20/JDS50
CX-JDS20/JDS50 are the Amplifier, CD player, Tape
Deck andTuner section in DBX-DS20/DBX-DS50.
— Continued on next page —
Model Name Using Similar Mechanism NEW
CD CD Mechanism Type BU-F1BD81A
Section Optical Pick-up Name KSM-215DCP/C2NP
TAPE Model Name Using Similar Mechanism CX-LEM330
Section Tape Transport Mechanism Type JDS20 CMAL5Z220A
JDS50 CMAL1Z240A
Photo : CX-JDS50
Other models:
JDS50
The following measured at AC 120, 127, 220, 240 V
50/60 Hz
DIN power output (rated): 160 + 160 watts (6 ohms at
1kHz, DIN)
Continuous RMS power output (reference):
200 + 200 watts (6 ohms at
1kHz, 10% THD)
JDS20
The following measured at AC 120, 127, 220, 240 V
50/60 Hz
DIN power output (rated): 96 + 96 watts (6 ohms at
1kHz, DIN)
Continuous RMS power output (reference):
120 + 120 watts (6 ohms at
1kHz, 10% THD)
Inputs
AUDIO IN (stereo mini jack):
voltage :
impedance 47 kilohms
MIC (phone jack) (except for European model):
se
JDS20: 0.25 mV
JDS50: 0.1 mV,
nsitivity:
impedance 10 kilohms
Outputs
PHONES (stereo mini jack):
accepts headphones of
8ohmsormore
SPEAKER: accepts impedance of 6 to
16 ohms
Amplifier section
European model:
JDS20
DIN power output (rated): 96 + 96 watts (6 ohms at
1kHz, DIN)
Continuous RMS power output (reference):
120 + 120 watts (6 ohms at
1kHz, 10% THD)
Music power output (reference):
180 + 180 watts (6 ohms at
1kHz, 10% THD)
Russian model:
JDS50
DIN power output (rated): 160 + 160 watts (6 ohms at
1kHz, DIN)
Continuous RMS power output (reference):
200 + 200 watts (6 ohms at
1kHz, 10% THD)
Music power output (reference):
330 + 330 watts (6 ohms at
1kHz, 10% THD)
JDS20
DIN power output (rated): 96 + 96 watts (6 ohms at
1kHz, DIN)
Continuous RMS power output (reference):
120 + 120 watts (6 ohms at
1kHz, 10% THD)
Music power output (reference):
180 + 180 watts (6 ohms at
1kHz, 10% THD)
JDS20: 1.85 V
JDS50: 0.9 V,

2
CX-JDS20/JDS50
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0OR DOTTED LINE
WITH MARK 0ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR
IN SUPPLEMENTS PUBLISHED BY SONY.
General
Power requirements
European and Russian models:
230 V AC, 50/60 Hz
Australian model: 230 – 240 V AC, 50/60 Hz
Argentine model: 220 V AC, 50/60 Hz
Mexican model: 127 V AC, 60 Hz
Other models: 120 V, 220 V or
230 – 240 V AC, 50/60 Hz
Adjustable with voltage
selector
Power consumption
European model:
JDS20: 198 watts
0.25 watts (at the Power
Saving Mode)
Other models:
JDS50: 160 watts
JDS20: 198 watts
Dimensions (w/h/d) (excl. speakers):
Approx. 230 × 365.5 ×
409 mm
Mass (excl. speakers) Approx. 9.1 kg
Design and specifications are subject to change
without notice.
CD player section
System Compact disc and digital
audio system
Laser Diode Properties Emission duration:
continuous
Laser Output: Less than
44.6 µW
(This output is the value
measurement at a distance
of 200 mm from the
objective lens surface on
the Optical Pick-up Block
with 7 mm aperture)
Frequency response 2 Hz – 20 kHz (±0.5 dB)
Signal-to-noise ratio More than 90 dB
Dynamic range More than 90 dB
Tape deck section
Recording system 4-track 2-channel, stereo
Frequency response 50 – 13,000 Hz (±3 dB),
using Sony TYPE I
cassettes
Tuner section
FM stereo, FM/AM superheterodyne tuner
FM tuner section
Tuning range 87.5 – 108.0 MHz
(50 kHz step)
Antenna FM lead antenna
Antenna terminals 75 ohms unbalanced
Intermediate frequency 10.7 MHz
AM tuner section
Tuning range
European and Russian models:
531 – 1,602 kHz (with the
tuning interval set at
9kHz)
Other models: 530 – 1,710 kHz
(with the tuning interval
set at 10 kHz)
531 – 1,602 kHz
(with the tuning interval
set at 9 kHz)
Antenna AM loop antenna
Antenna terminals External antenna terminal
Intermediate frequency 450 kHz
Pan-American models: 530 – 1,710 kHz
(with the tuning interval
set at 10 kHz)
531 – 1,710 kHz
(with the tuning interval
set at 9 kHz)
•Abbreviation
AUS:Australian model
E51 : Chilean and Peruvian models
MX : Mexican model
RU : Russian model
Model Part No.
JDS50: MX model 2-595-343-0[]
JDS20: MX model 2-595-345-0[]
JDS50: E51 model 2-595-523-0[]
JDS20: E51 model 2-595-525-0[]
JDS50: RU model 2-599-602-0[]
JDS20: AEP, RU models 2-599-608-0[]
JDS20: AUS model 2-599-613-0[]
MODEL IDENTIFICATION
– BACK PANEL –
3
#
#
3
Part No.

3
CX-JDS20/JDS50
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.
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 from more than 30 cm away from the objective lens.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
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 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.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation
exposure.
UNLEADED SOLDER
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)
: LEAD FREE MARK
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 viscou-s (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.
Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.
This appliance is classified as a CLASS 1 LASER product.
The CLASS 1 LASER PRODUCT MARKING is located on the
exterior.
The release method of a CD disc tray LOCK function
There is a disc lock function for the disc theft prevention for a
demonstration at a shop front in this machine.
Procedue:
1. Press the ?/1button to turn the set on.
2. Press two buttons of xand Zsimultaneously for five
seconds.
3. The message “LOCKED” is displayed and the tray is
locked. (Even if exiting from this mode, the tray is still
locked.)
4. Press two buttons of xand Zsimultaneously for five
seconds again.
5. The message “UNLOCKED” is displayed and the tray is
unlocked.
6. To exit from this mode, press the ?/1button to turn the
set off.

4
CX-JDS20/JDS50
TABLE OF CONTENTS
1. GENERAL ................................................................... 5
2. DISASSEMBLY
2-1. Disassembly Flow ........................................................... 7
2-2. Top Panel, Side Panel ...................................................... 8
2-3. Front Section ................................................................... 8
2-4. CD Mechanism Section ................................................... 9
2-5. Cassette Mechanism Deck, DS-PAI/HP/MIC Board ...... 9
2-6. DS-PANEL Board ........................................................... 10
2-7. Rear Cabinet .................................................................... 10
2-8. Power Trans ..................................................................... 11
2-9. DS-MAIN Board, Heat Sink ........................................... 11
2-10. Holder (CD Mech) ........................................................... 12
2-11. Base Unit (BU-F1BD81A), CD Mech ............................ 12
2-12. BD Board, Optical Pick-up (KSM-215DCP/C2NP) ....... 13
2-13. Frame ............................................................................... 13
2-14. Belt .................................................................................. 14
2-15. Cassette Panel .................................................................. 15
3. TEST MODE ............................................................... 16
4. MECHANICAL ADJUSTMENTS......................... 17
5. ELECTRICAL ADJUSTMENTS .......................... 17
6. DIAGRAMS
6-1. Block Diagram – MAIN Section – ................................. 22
– BD Section – ................................................................ 23
6-2. Printed Wiring Board – BD Section – ............................ 24
6-3. Schematic Diagram – BD Section – ............................... 25
6-4. Printed Wiring Board – MAIN (JDS20) Section – ......... 26
6-5. Printed Wiring Board – MAIN (JDS50) Section – ......... 27
6-6. Schematic Diagram – MAIN Section (1/2) – ................. 28
6-7. Schematic Diagram – MAIN Section (2/2) – ................. 29
6-8. Printed Wiring Board
– PANEL (JDS20/JDS50) Section – ............................... 30
6-9. Schematic Diagram – PANEL Section (1/2) – ............... 31
6-10. Schematic Diagram – PANEL Section (2/2) – ............... 32
6-11. Printed Wiring Board
– PANEL COMB (JDS20) Section – .............................. 33
6-12. Printed Wiring Board
– PANEL COMB (JDS50) Section – .............................. 34
6-13. Schematic Diagram – PANEL COMB Section – ........... 35
6-14. Printed Wiring Board – AMP (JDS20) Section – ........... 36
6-15. Printed Wiring Board – AMP (JDS50) Section – ........... 37
6-16. Schematic Diagram – AMP (JDS20) Section –.............. 38
6-17. Schematic Diagram – AMP (JDS50) Section –.............. 39
6-18. Printed Wiring Board
– POWER (JDS20/JDS50) Section – .............................. 40
6-19. Schematic Diagram – POWER Section – ...................... 41
7. EXPLODEDVIEWS
7-1. Overall Section ................................................................ 50
7-2. Front Section ................................................................... 51
7-3. Chassis Section ................................................................ 52
7-4. CD Mechanism Section-1 ............................................... 53
7-5. CD Mechanism Section-2 ............................................... 54
8. ELECTRICAL PARTS LIST .................................. 55

5
CX-JDS20/JDS50
SECTION 1
GENERAL This section is extracted
from instruction manual.
Main unit
AUDIO IN jack w; (28)
BASS control qf (21)
CANCEL wl (11)
CD SYNC wk (18)
Cassette compartment qh (17)
DISC 1 – 3 4(10)
DISC SKIP/EX-CHANGE 5
(10, 13, 18)
Disc tray 6(9)
DISPLAY qd (16, 25, 26)
Display window 3
ENTER wf (11, 13, 14)
EQ 0(20)
FM MODE wd (16)
FUNCTION wj (9, 13, 14, 15, 17,
18, 19, 21, 28)
i-Bass 9(20, 31)
MIC jack1) qj (21)
MIC LEVEL1) qk (21)
MIDDLE control qs (21)
Jog dial ws (11, 13)
PHONES jack ql
PLAY MODE wg (10, 13, 17)
REC PAUSE/START 8(18, 19,
21)
Remote sensor 2
REP wd (12)
TREBLE control qa (21)
TUNER/BAND wh (14, 15)
TUNING +/– wl (14, 15)
TUNING MODE wg (14, 15)
VOLUME control wa (27)
?/1 (power) 1(7, 15)
Z(eject) 7(9)
ZPUSH (eject) qg (17)
lm/ML (rewind/fast
forward, go back/go forward)
wl (10, 17)
x(stop) wl (10, 17, 18, 21, 27,
31)
N2) or nN3) (play) wl (10,
17, 18)
X(pause) wl (10, 17, 31)
1) Except for European model
2) DBX-DS20
3) DBX-DS50
List of button locations and reference pages
How to use this page
Use this page to find the location of buttons and other
parts of the system that are mentioned in the text.
Ill
us
t
ra
ti
on num
b
er
r
TUNER/BAND wh (14, 15)
RR
Name of button/part Reference page
ALPHABETICAL ORDER
A – N M – Z
BUTTON DESCRIPTIONS
qf
w;
ql
qg
qh
qk
qj
wd
wa
ws
wf
wg
wj
wh
wk
wl
1 762 3 54
8
9
0
qa
qs
qd

6
CX-JDS20/JDS50
Remote control
CD qk (9, 12)
CLEAR qg (13)
CLOCK/TIMER SELECT 2
(24, 25)
CLOCK/TIMER SET 3(8, 23,
24)
DISC SKIP q; (10, 12)
DISPLAY wa (16, 25, 26)
ENTER 9(8, 12, 14, 23, 24)
EQ qf (20)
FM MODE 4(16)
FOLDER + qa (10, 12, 18)
FOLDER – qd (10, 12, 18)
FUNCTION 6(9, 12, 14, 15, 17,
28)
PLAY MODE w; (10, 12, 17)
REPEAT 4(12)
SLEEP ws (23)
TAPE qj (17)
TUNER BAND 5(14, 15)
TUNER MEMORY ql (14)
TUNING MODE w; (14, 15)
VOLUME +/– qs (23)
?/1 (power) 1(7, 24)
m/M (rewind/fast forward)
7(10, 17)
N(play) 8(10, 17)
X(pause) 8(10, 17)
x(stop) 8(10, 17)
+/– (tuning) qh (14)
./> (go back/go forward)
qh (8, 10, 23)
ALPHABETICAL ORDER
A – E F – Z
BUTTON DESCRIPTIONS
4
5
6
7
8
9
q;
ws 1
qd
qg
qf
wa
w;
ql
qk
qj
qh
qa
qs
3
2
Use buttons on the remote for the operation.
1 Press ?/1 to turn on the system.
2 Press CLOCK/TIMER SET.
3 Press .or >repeatedly to set the
hour.
4 Press ENTER.
5 Press .or >repeatedly to set the
minute.
6 Press ENTER.
The clock starts working.
To adjust the clock
1 Press CLOCK/TIMER SET.
2 Press .or >repeatedly to select
“CLOCK SET”, then press ENTER.
3 Do the same procedures as step 3 to 6
above.
Notes
The clock settings are canceled when you disconnect
the power cord or if a power failure occurs.
You cannot set the clock in Power Saving Mode
(page 25).
Setting the clock

7
CX-JDS20/JDS50
SECTION 2
DISASSEMBLY
2-1. DISASSEMBLY FLOW
•This set can be disassembled in the order shown below.
SET
2-2.TOP PANEL, SIDE PANEL
(Page 8) 2-15. CASSETTE PANEL (Page 15)
2-3. FRONT SECTION
(Page 8)
2-7. REAR CABINET
(Page 10) 2-10. HOLDER (CD MECH) (Page 12)
2-14. BELT
(Page 14)
2-8. POWER TRANS
(Page 11) 2-11. BASE UNIT (BU-F1BD81A),
CD MECH
(Page 12)
2-4. CD MECHANISM SECTION
(Page 9) 2-6. DS-PANEL BOARD (Page 10)
2-5. CASSETTE MECHANISM DECK,
DS-PAI/HP/MIC BOARD
(Page 9)
2-9. DS-MAIN BOARD,
HEAT SINK
(Page 11)
2-13. FRAME
(Page 13)
2-12. BD BORD, OPTICAL PICK-UP
(KSM-215DCP/C2NP)
(Page 13)

8
CX-JDS20/JDS50
Note: Follow the disassembly procedure in the numerical order given.
2-2. TOP PANEL, SIDE PANEL
2-3. FRONT SECTION
qa top panel
2 two screws
(+BVTP 3
× 10)
5 two screws
(+BVTP 3
× 10)
7 three screws
(+BVTP 3
× 10)
3 right panel
6 left panel
1 four screws
(Case 3)
4 four screws
(Case 3)
q;
9
8
9 front section
5 three screws
(+BVTP)(B3)
6 screw
(+BVTP)(B3)
8 screw
(+BVTP)(B3)
7 screw
(+KTP 3
× 6)
1 wire (flat type)
(11core) (CN112)
2 wire (flat type)
(15core) (CN604)
4 wire (flat type)
(27core) (CN604)
3 connector
(6p) (cassette deck)

9
CX-JDS20/JDS50
2-4. CD MECHANISM SECTION
2-5. CASSETTE MECHANISM DECK, DS-PAI/HP/MIC BOARD
1 two screws
(+BVTP)(B3)
2 CD mechanism section
2 wire (flat type)
(8core)
1 three screws
(+PTP)(B2.6)
3 three screws
(+PTP)(B2.6)
5 two screws
(+PTP)(B2.6)
6 holder
(PWB MIC)
7 DS-PAI/HP/MIC board
4 cassette mechanism deck

10
CX-JDS20/JDS50
2-6. DS-PANEL BOARD
2-7. REAR CABINET
1 knob (RTRY)
3 knob (RTRY AMS)
2 guide (LED VOL)
4 twenty screws
(+PTP)(B2.6)
6 DS-PANEL board
3 connector
(11p) (CN651)
2 wire (flat type)
(11core)
1 connector
(2p) (CN871)
3 four screws
(+BVTP)(B3)
4 rear cabinet

11
CX-JDS20/JDS50
2-8. POWERTRANS
2-9. DS-MAIN BOARD, HEAT SINK
1 four screws
3 power trans
2 cord bushing
5 DS-MAIN board
4 connector
6 heat sink
1 two screws
(+BVTP)(B3)
3 screw
(+BVTP)(B3)
2 two screws
(+BVTP)(B3)

12
CX-JDS20/JDS50
2-10. HOLDER (CD MECH)
2-11. BASE UNIT (BU-F1BD81A), CD MECH
2 wire (flat type)
(27 core) (CN606)
4 wire (flat type)
(27 core)
3 tape
5 s crew (+BVTP 2.6 × 8)
6 DS CONN board
7 holder (CD MECH)
1 four s crews (+BVTP 2.6 × 8)
2 two coil springs
(insulator)
4 two coil springs
(insulator)
1 two floating screws
(+PTPWH M2.6)
3 two floating screws
(+PTPWH M2.6)
6 base unit
(BU-F1BD81A)
7 tray panel
8 CD mech
5 wire (flat type)
(27 core)

13
CX-JDS20/JDS50
2-12. BD BOARD, OPTICAL PICK-UP (KSM-215DCP/C2NP)
6 two insulators
7 two insulators
2 gap tube
5 B D board
8 optical pick-up
(KSM-215DCP/C2NP)
1 s crew (+BVTP 2.6 × 8)
4 Remove the four solderings of motor.
3 wire (flat type)
(16 core)
2-13. FRAME
1 four s crew
s
2 frame

14
CX-JDS20/JDS50
2-14. BELT
2 Slide the upper-most tray foward the front.
1 Release the hook of the tray.
3 While pushing up the plate cam,
d
raw the Drawer (three trays) entirely foward front.
4 two belts
plate cam

15
CX-JDS20/JDS50
2-15. CASSETTE PANEL
4 cassette panel
3 two claws
2 Open the
cassette panel.
1 Push the
cassette panel.

16
CX-JDS20/JDS50 SECTION 3
TEST MODE
[COLD RESET]
*The cold reset clears all data including preset data stored in
the RAM to initial conditions. Execute this mode when
returning the set to the customer.
Procedure:
1. Press the ?/1button to turn the set on.
2. Press three buttons x, Xand [i-Bass] simultaneously.
3. The fluorescent indicator tube does not display any message
and the set is reset.
[Version Display Mode]
*The version of the microcomputer is displayed.
Procedure:
1. Press the ?/1button to turn the set on.
2. To enter the test mode, press three buttons x, [DISPLAY]
and ?/1simultaneously. The version of the microcomputer
is displayed.
[PANELTest]
*All fluorescent segments are tested.
Procedure:
1. Press the ?/1button to turn the set on.
2. Press three buttons x, [DISPLAY] and ?/1simultaneously.
3. Then all segments of the florescent indicator tube are turned
on.
[KEYTest]
*Keyboard check
Procedure:
1. When the panel test mode is activated. Press xand [DISC 1]
buttons simultaneously, and the key check mode is activated.
2. The message “KEY 0 0 0” is displayed.
3. Press x, and [DISC 1] buttons simultaneously, and the key
count mode is activated.
4. The message “KEYCNT 0” is displayed.
Each time a button is pressed, “KEYCNT 0” value increased.
However, once a button is pressed, it is no longer take into
account.
[CD Ship (LOCK) & COLD RESET MODE]
Procedure:
1. Press the ?/1button to turn the set on.
2. Select the function “CD”.
3. Press the ?/1button to turn the set off.
4. Press three buttons x, [i-Bass] and [DISC 3] simultaneously.
5. The “LOCK” display blinks instantaneously and CD ship mode
is set.
6. The Cold Reset Mode is set.
[CD Ship Mode]
*This mode moves the optical pick-up to the position durable
to vibration. Use this mode when returning the set to the
customer after repair.
Procedure:
1. Press the ?/1button to turn the set on.
2. Set the FUNCTION to CD.
3. Press three buttons x, ML and [DISPLAY] simulta-
neously for more than two seconds.
4. After a message “LOCK” is displayed on the fluorescent
indicator tube, the CD ship mode is set and the power is turned
off.
[DiscTray Lock]
The disc tray lock function for the antitheft of an demonstration
disc in the store is equipped.
Setting Procedure :
1. Press the ?/1button to turn the set on.
2. Press two buttons of xand Zsimultaneously for five
seconds.
3. The message “LOCKED” is displayed and the tray is locked.
Releasing Procedure :
1. Press two buttons of xand Zsimultaneously for five
seconds again.
2. The message “UNLOCKED” is displayed and the tray is
unlocked.
Note : When “LOCKED” is displayed, the tray lock is not released
by turning power on/off with the ?/1button.
[CommonTest]
*This mode is used to check the function of the amplifier.
Procedure:
1. Press the ?/1button to turn the set on.
2. Press three buttons x, [DISPLAY] and ?/1simultaneously.
3. The message “Volume MAX” is displayed, when the
[VOLUME] knob is rotated clockwise. The message “Volume
MIN” is displayed, when the [VOLUME] knob is rotated
counterclockwise.
4. Each time the [BASS] , [TREBLE] and [MIDDLE] knob is turned,
the message “EQ MAX”, “EQ MIN” or “EQ FLAT” is
displayed in this order.
[AM Channel Step 9 kHz/10kHz Selection Mode]
*Either the 9 kHz step or 10 kHz step can be selected for the
AM channel step. (EXCEPT AEP,UK,RU)
Procedure:
1. Set the FUNCTION to AM.
2. While depressing the [PLAY MODE/TUNING MODE] button,
press the ?/1button.
3. The channel step is changed over.
[CD Repeat 5Times Limit Release Mode]
Procedure:
1. Press the ?/1button to turn the set on.
2. Select the FUNCTION to CD.
3. Press three buttons x, [DISPLAY] and [DISC 1] simulta-
neously.
4. The repeat all mark blinks and then repeat 5 times limit is
released.

17
CX-JDS20/JDS50
2.94 – 7.84 mN • m
(30 to 79 g • cm)
(0.42 – 1.11 oz • inch)
0.15 – 0.59 mN • m
(2 to 6 g • cm)
(0.03 – 0.08 oz • inch)
2.94 – 7.84 mN • m
(30 to 79 g • cm)
(0.42 – 1.11 oz • inch)
0.15 – 0.59 mN • m
(2 to 6 g • cm)
(0.03 – 0.08 oz • inch)
6.86 – 17.64 mN • m
(70 to 179 g • cm)
(0.98 – 2.49 oz • inch)
0.98 mN • m or more
(10 • cm or more)
(0.14 oz • inch or more)
0.98 mN • m or more
(10 • cm or more)
(0.14 oz • inch or more)
CQ-102C
CQ-102C
CQ-102RC
CQ-102RC
CQ-201B
CQ-403A
CQ-403R
TAPE MECHANISM DECK SECTION
Precaution
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback heads pinch rollers
erase head rubber belts
capstan idlers
2. Demagnetize the record/playback head with a head demag-
netizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to
the parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
Torque Measurement
Mode
FWD
FWD
back tension
REV
REV
back tension
FF/REW
FWD tension
REV tension
Torque meter Meter reading
Record/Playback Head Azimuth Adjustment
Procedure:
1. Mode : Playback
2. Turn theadjustmentscrew andcheckoutputpeaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1 dB of peak.
DECK SECTION 0 dB=0.775V
Precaution
1. Demagnetize the record/playback head with a head
demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to
the parts adjusted.
4. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
5. The adjustments should be performed in the order given in
this service manual. (As a general rule, playback circuit
adjustment should be completed before performing recording
circuit adjustment.)
6. The adjustments should be performed for both L-CH and R-
CH.
7. Switchesandcontrols should be setasfollows unless otherwise
specified.
• Test Tape
Signal Used forTape
P-4-A100
WS-48B
10 kHz, –10 dB
3 kHz, 0 dB
Azimuth Adjustment
Tape Speed Check
SECTION 4
MECHANICAL ADJUSTMENTS SECTION 5 ELECTRICAL ADJUSTMENTS
set
DS-MAIN board
SPEAKER terminal (J171)
L-CH, R-CH
+
–
level meter
test tape
P-4-A100
(10 kHz, –10 dB)
Screw
position
L-CH
peak
within
1dB
Output
level
L-CH
peak R-CH
peak
within
1dB
Screw
position
R-CH
peak

18
CX-JDS20/JDS50
4. After the adjustments, apply suitable locking compound to
the parts adjusted.
Adjustment Location: Record/Playback/Erase Head
3. Mode: Playback
set
test tape
P-4-A100
(10 kHz, –10 dB)
R-CH
oscilloscope
L-CH
R-CH
VH
waveform of oscilloscope
in phase 45 ° 90 ° 135 ° 180 °
good wrong
DS-MAIN board
SPEAKER terminal (J171)
L-CH
Tape Speed Check
Mode: Playback
1. Insert the WS-48B into deck.
2. Press the nN button of deck.
3. Confirm that the frequency counter reads 3000 ±90 Hz.
Sample Value of Wow and flutter: 0.3% or less W.RMS (JIS)
(WS-48B)
+
–
set
test tape
WS-48B
(3 kHz, 0 dB)
DS-MAIN board
SPEAKER terminal (J171)
L-CH, R-CH
frequency counter
Record Bias Adjustment
Procedure:
1. Record mode
2. Mode: Playback
i-Bass OFF
BASS 0
TREBLE 0
3. Confirm playback the signal recorded in step 1 become
adjustment level as follows.
Adjustment level: Playback output of 315 Hz to playback output
of 10 kHz: –2 ±3.0 dB (0 ±4.5mV).
attenuator
set
DS-MAIN board
AUX IN (J552)
1) 315 Hz
2) 10 kHz 50 mV (–23.8 dB)



600 Ω
blank tape
CN-123
AF OSC
+
–
set
recorded
portion
DS-MAIN board speaker terminal (J171
)
level meter
Note: Refer to “2-15. Cassette Panel” (see page 15)
adjustment screw

19
CX-JDS20/JDS50
CD SECTION
Note:
1. UseYEDS-18 disc (3-702-101-01) unless otherwiseindicated.
2. Use an oscilloscope with more than 10MΩimpedance.
3. Clean the object lens by an applicator with neutral detergent
when the signal level is low than specified value with the
following checks.
S-curve Check
Connection:
Procedure:
1. Connect an oscilloscope to test point TP (FEO) and TP (VC)
on the BD board.
2. Set the FUNCTION to “CD”.
3. While depressing the nN button, insert anAC plug.
4. Put the disc (YEDS-18) in and press the xbutton and actuate
the focus search. (actuate the focus search when disc table is
moving in and out)
5. Check the oscilloscope waveform (S-curve) is symmetrical
betweenA and B.And confirm peak to peak level within 2 ±1
Vp-p.
Note: •Try to measure several times to make sure than the ratio ofA : B
or B : A is more than 10 : 7.
•Take sweep time as long as possible and light up the
brightness to obtain best waveform.
Checking Location: BD board (Side B)(See page 20)
RFDC Level Check
Connection:
Procedure:
1. Connect an oscilloscope to test point (RFDCO) and TP (VC)
on the BD board.
2. Turn the power on.
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RFDC
signal level is correct or not.
Note: A clear RFDC signal waveform means that the shape “◊” can
be clearly distinguished at the center of the waveform.
Checking Location: BD board (Side B)(See page 20)
RFAC Level Check
Connection:
Procedure:
1. Connect an oscilloscope to test point TP (RFACO) and TP
(VC) on the BD board.
2. Turn the power on.
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RFAC
signal level is correct or not.
Note: A clear RFAC signal waveform means that the shape “◊” can
be clearly distinguished at the center of the waveform.
Checking Location: BD board (Side B)(See page 20)
+
–
BD board
oscilloscope
TP (FED)
TP (VC)
S-curve waveform
symmetry
A
B
within 2
± 1 Vp-
p
+
–
BD board
oscilloscope
TP (RFDCO)
TP (VC)
RFDC signal waveform VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 0.6
± 0.15 Vp-p
+
–
BD board
oscilloscope
TP (RFACO)
TP (VC)
RFAC signal waveform VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 1.0
± 0.4 Vp-p

20
CX-JDS20/JDS50
E-F Balance Adjustment
Connection:
Procedure:
1. Connect an oscilloscpe to test point TP (TEO) and TP (VC)
on the BD board.
2. Set the FUNCTION to “CD”.
3. AC is put in pushing nN button to enter the CD test mode.
4. Put the disc (YEDS-18) in to playback the number five track.
5. Press the nN button. If it plays, press the nN button
again. (The tracking servo and the sledding servo are turned
OFF)
6. Check the level B of the oscilliscope’s waveform and the A
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than ±10%
7. Press the nN button. (The tracking servo and sledding
servo are turned ON)
8. To exit from this mode, turn the power off.
Notes:•Alwaysmovethe optical pick-upto most insidetrack when exiting
from this mode. Otherwise, a disc will not be unloaded.
•Do not run the sled motor excessively, otherwise the gear can be
chipped.
Checking Location: BD board (Side B)
Checking Location:
– BD BOARD (Side B) –
+
–
BD board
oscilloscope
TP (TEO)
TP (VC)
Traverse Waveform
0V
Center of
the waveform
BA (DC
voltage
)
level: 1.0 ± 0.5 Vp-p
Traverse Waveform
0V
Tracking servo
Sled servo
OFF
Tracking servo
Sled servo
ON
C (DC
voltage)
IC251
IC301
IC101
IC303
TP
(RFACO)
TP
(VC)
TP
(FEO)
TP
(RFDCO)
TP
(TEO)