Sony HCD-DX70 User manual

Model Name Using Similar Mechanism NEW
CD Mechanism Type CDM58E-30BD60
Base Unit Type BU-30BD60
Optical Pick-up Type A-MAX.3
Model Name Using Similar Mechanism NEW
Tape Transport Mechanism Type TCM-230AWR41/MWR41
HCD-DX70
SERVICE MANUAL
HCD-DX70 is the tuner, deck, CD and amplifier
section in MHC-DX70.
SPECIFICATIONS
COMPACT DISC DECK RECEIVER
— Continued on next page —
CD
SECTION
TAPE DECK
SECTION
E Model
Ver 1.0 2001.02
Sony Corporation
Audio Entertainment Group
General Engineering Dept.
9-929-580-11
2001B0900-1
© 2001.2

2
HCD-DX70
TABLE OF CONTENTS
1. GENERAL ·········································································· 4
2. DISASSEMBLY
2-1. Case (Top) ·········································································· 5
2-2. Loading Panel ····································································· 6
2-3. Front Panel Section ···························································· 6
2-4. Tape Mechanism Deck ······················································· 7
2-5. CD SW Board, Panel Board, Pad Switch Board ················ 7
2-6. Main Trans Board ······························································· 8
2-7. Main Board, Power Board ·················································· 8
2-8. SW Board, Head (A) Board, Head (B) Board ···················· 9
2-9. Base Unit ············································································ 9
2-10. Driver Board, Motor Board, CD Sensor Board and
Video Board ······································································ 10
3. TEST MODE ···································································· 11
4. MECHANICAL ADJUSTMENTS ····························· 15
5. ELECTRICAL ADJUSTMENTS ······························· 15
6. DIAGRAMS
6-1. Circuit Board Location ····················································· 21
6-2. Block Diagrams ································································ 22
6-3. Schematic Diagram – BD Section – ································· 24
6-4. Printed Wiring Board – BD Section – ······························ 25
6-5. Printed Wiring Board – Main Section – ··························· 26
6-6. Schematic Diagram – Main (1/4) Section – ····················· 27
6-7. Schematic Diagram – Main (2/4) Section – ····················· 28
6-8. Schematic Diagram – Main (3/4) Section – ····················· 29
6-9. Schematic Diagram – Main (4/4) Section – ····················· 30
6-10. Schematic Diagram – Video SW Section – ······················ 31
6-11. Printed Wiring Board – Video SW Section – ··················· 31
6-12. Printed Wiring Board – Power AMP Section – ················ 32
6-13. Schematic Diagram – Power AMP Section – ··················· 33
6-14. Printed Wiring Board – Panel Section – ··························· 34
6-15. Schematic Diagram – Panel Section – ····························· 35
6-16. Printed Wiring Boards – Switch Section – ······················· 36
6-17. Schematic Diagram – Switch Section – ··························· 37
6-18. Printed Wiring Boards – Leaf SW Section – ···················· 38
6-19. Schematic Diagram – Leaf SW Section – ························ 39
6-20. Printed Wiring Boards – Driver Section – ························ 40
6-21. Schematic Diagrams – Driver Section – ·························· 41
6-22. Printed Wiring Board – Trans Section – ··························· 42
6-23. Schematic Diagram – Trans Section – ····························· 43
6-24. IC Pin Functions ······························································· 44
6-25. IC Block Diagrams ··························································· 48
7. EXPLODED VIEWS
7-1. Main Section ····································································· 51
7-2. Front Panel Section ·························································· 52
7-3. Chassis Section ································································· 53
7-4. Tape Mechanism Section-1 (TCM-230MWR41) ············· 54
7-5. Tape Mechanism Section-2 (TCM-230AWR41) ·············· 55
7-6. CD Mechanism Deck Section (CDM58E-30BD60) ········ 56
7-7. Base Unit Section (BU-30BD60) ····································· 57
8. ELECTRICAL PARTS LIST ······································· 58

3
HCD-DX70
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.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
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.
MODEL IDENTIFICATION
— BACK PANEL —
PARTS No.
•Abbreviation
AR : Argentina model
SP : Singapore model
MX : Mexican model
E51 : Chiri and Peru model
MODEL
E, E51, AR, SP models
MX model
PARTS No.
4-231-580-1s
4-231-580-3s
SETTING THE TIME
This section is extracted
from instruction manual.

4
HCD-DX70
Location of Parts and Controls
1@/1 (POWER) button and indicator
2DISC 1 button and indicator
3DISC 2 button and indicator
4DISC 3 button and indicator
5DISC SKIP EX-CHANGE button
6CD (OPEN) button
7CD button and indicator
8TUNER/BAND button and indicator
9TAPE A/B button and indicator
q; MD (VIDEO) button and indicator
qa VOLUME knob
qs PHONES jack
qd MIC jack
qf MIC LEVEL knob
qg GAME INPUT (VIDEO, AUDIO L/R) jack
qh GAME button and indicator
qj DISPLAY button
qk SPECTRUM button
ql EDIT (DIRECTION) button
w; REPEAT (FM MODE/DOLBY NR) button
wa PLAY MODE (TUNER MEMORY) button
SECTION 1
GENERAL
Front Panel
qj qk ql w;wa ws
1 2 3 4 56
7
9
qa
qs
8
q;
qh
qf
qd
qg
eheg ed es e;wk wh
wjef ea wl
el r;
ej ek
ra
wf
wg
wd
ws Remote sensor
wd MOVIE EQ button
wf ENTER button and indicator
wg P FILE button
wh M/+ button
wj REC PAUSE/START button and indicator
wk >button
wl CD SYNC HI-DUB button
e; Xbutton
ea SURROUND button
es bB button
ed xbutton
ef GROOVE button
eg .button
eh m/– button
ej b/v/B/V button
ek GAME EQ button
el KARAOKE PON button
r; EFFECT ON/OFF button
ra MUSIC EQ button

5
HCD-DX70
SECTION 2
DISASSEMBLY
Note : Follow the disassembly procedure in the numerical order given.
2-1. CASE (TOP)
Set Case (Top) Loading Panel Front Panel Section
Tape Mechanism Deck
CD SW Board, Panel Board And PAD Switch Board
Head (A) Board, Head (B) Board And SW Board
Main Trans Board
Main Board And Power Board
Base Unit
Driver Board, Motor Board, CD Sensor Board And Video Board
• The equipment can be removed using the following procedure.
4
qs
9
8
two screws
(+BVTP 3
× 10)
1 two screws (case 3 TP2)
6 two screws (case 3 TP2)
qd case (top)
7 screw (case 3 TP2)
5 side panel (R)
0 side panel (L)
2 screw (case 3 TP2)
qa two screws (+BVTP 3 × 12)
two claws
two claws
3 two screws
(+BVTP 3
× 10)

6
HCD-DX70
2-2. LOADING PANEL
2-3. FRONT PANEL SECTION
2 Pull-out the disc tray.
4 Pull-out the disc tray.
1 Turn the pulley to the direction of arrow.
pulley
Front panel side
CD mechanism deck (CDM58)
3
8
3
connector (CN2)
4 connector
(CN607)
0 connector
(CN781)
qa flat type wire
(CN201)
qs connector
(CN202)
2 connector (CN1) connector
(CN601)
lead wire
lead wire
1 flat type wire (CN304)
qg CD mechanism deck (CDM58)
7 three screws (+BVTT 3 × 8)
9 front panel section
5 screw
(+BVTP 3 × 10)
qh screw (+BVTP 3 × 10)
qj screw
(+BVTP 3 × 10)
qd screw (+BVTP 3 × 10)
6 screw
(+BVTP 3 × 10)
qf

7
HCD-DX70
2-4. TAPE MECHANISM DECK
2-5. CD SW BOARD, PANEL BOARD, PAD SWITCH BOARD
2 Tape mechanism deck
1 five screws (+BVTP 2.6 × 8)
2 four claws
1 four screws
(+BVTP 2.6
× 8)
4 six screws
(+BVTP 2.6
× 8)
5 three screws
(+BVTP 2.6
× 8)
0 three screws
(+BVTP 2.6
× 8)
qa five screws
(+BVTP 2.6
× 8)
qd PAD SWITCH board
7 PANEL board
6 two claws
qs claw
3 CD SW board
8 knob vol
9 nut

8
HCD-DX70
2-6. MAIN TRANS BOARD
2-7. MAIN BOARD, POWER BOARD
qa two screws
(+BVTT 4
× 8)
8 six screws
(+BVTP 3
× 10)
7 three screws
(+BVTP 3
× 10)
9 panel, back
0 two screws (+BVTT 4 × 8)
qd TRANS board
qs trans
5 connector (CN973)
2 SENSOR board
6 connector (CN977)
3 connector (CN891)
4 connector (CN403)
1 screw
(+BVTP 3
× 10)
4 three screws (+BVTP 3 × 10)
6 two screws (+BVTT 3 × 8)
7 heat sink
3 two screws (+BVTP 3 × 16)
1 two screws (+BVTP 3 × 10)
2 MAIN board
connector(CN502)
connector
(CN503)
5 POWER board

9
HCD-DX70
2-8. SW BOARD, HEAD (A) BOARD, HEAD (B) BOARD
2-9. BASE UNIT
4 screw (+PTT 2 × 4),
ground point
4 screw (+PTT 2 × 4),
ground point
2 SW board
1 five claws
5 HEAD (A) board
6 HEAD (B) board
3 Remove the four solderings.
5
3
two screws (+PTPWH M2.6), floating
9 two springs (insulator), coil
7 two springs (insulator),
coil
0 two insulators (BU-30)
qa base unit
8 two insulators
(BU-30)
6 two stoppers (BU)
2 screw (DIA. 12), floating
1 flat type wire (CN101)
4 two screws
(+BVTP 2.6
× 8)

10
HCD-DX70
2-10. DRIVER BOARD, MOTOR BOARD, CD SENSOR BOARD AND VIDEO BOARD
3 two screws (+BVTP 2.6 × 8)
8 screw (+PTPWH 2.6 × 8)
9 tray
1 screw (+BVTP 2.6 × 8)
0 screw (+BVTP 2.6 × 8)
6 flat type wire (CN721)
5 MOTOR board
qa CD SENSOR board
7 connector(CN722)
2 DRIVER board
4 Remove the two solderings of motor.

11
HCD-DX70
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 three buttons x, ENTER , and ?/1simultaneously.
2. The fluorescent indicator tube becomes blank instantaneously,
and the set is reset.
[Hot Reset]
• This mode resets the set with the preset data kept stored in the
memory. The hot reset mode functions same as if the power
cord is plugged in and out.
Procedure:
1. Press three buttons x, ENTER , and DISPLAY
simultaneously.
2. The fluorescent indicator tube becomes blank instantaneously,
and the set is reset.
[Tuner Step Change]
• A step ofAM channels can be changed over between 9 kHz and
10 kHz.
Procedure:
1. Press ?/1button to turn the set ON.
2. Select the function “TUNER”, and press TUNER/BAND button
to select the BAND “AM”.
3. Press ?/1button to turn the set OFF.
4. Press ENTER and ?/1buttonssimultaneously, and the display
of fluorescent indicator tube changes to “AM 9 k STEP” or
“AM 10 k STEP”, and thus the channel step is changed over.
[Function Change Mode]
• Select either VIDEO or MD of the external FUNCTION input.
Procedure:
1. Turn on the power.
2. Hold down MD (VIDEO) button then press ?/1 button , and
release ?/1button first in order not to switch off the set
immediately.
The another function of the previous function is selected , the
input level is also changed and displayed “ MD ” or “VIDEO”.
[GCTest Mode]
• This mode is used to check the software version, FL tube, LED,
keyboard and VACS.
Procedure:
1. Press three buttons x, ENTER ,and DISC 2 simultaneously.
2. LEDs and fluorescent indicator tube are all turned on.
3. When you want to enter the software version display mode,
press DISC 1 . Themodel numberand destinationaredisplayed.
4. Each time DISC 1 is pressed, the display changes starting
from MC version, GC version, CD version, CDDM version,
CDMA version, CDMB, version BDA version, BDB version,
ST version, TA version, TM version and TC version in this
order, and returns to the model number and destination display.
5. When DISC 3 is pressed while the version numbers are being
displayed except model number and destination, year, month
and day of the software creation appear. When DISC 3 is
pressedagain, the display returns tothe softwareversion display.
When DISC 1 is pressed while year, month and day of the
software creation are being displayed, the year, month and day
of creation of the software versions are displayed in the same
order of version display.
6. Press DISC 2 button, and the key check mode is activated.
7. In the key check mode, the fluorescent indicator tube displays
“K0V0”. Each time abutton ispressed, “KEY” value increases.
However, once a button is pressed, it is no longer taken into
account.
“VOL” value increases like 1, 2, 3 ... if rotating VOLUME
knob in “+” direction, or it decreases like 0, 9, 8 ... if rotating in
“–” direction.
8. Also when DISC 3 is pressed after lighting of all LEDs and FL
tubes, value of VACS appears.
9. To exit from this mode, press three buttons in the same manner
as step 1, or disconnect the power cord.
[MCTest Mode]
• This mode is used to check operations of the respective sections
of Amplifier, Tuner, and Tape.
Procedure:
* To enter MC Test Mode
1. Press the ?/1button to turn on the set.
2. Press the three buttons of x, ENTER and DISC 3
simultaneously.
3. The messages MUSIC, MOVIE, GAME and P FILE flash on
the FL display tube.
The input FUNCTION is Changed to VIDEO.
* Check of Amplifier
1. When f(CURSOR UP) button is pressed, GEQ increases to
its maximum and a message “GEQ MAX” appears.
2. When F(CURSOR DOWN) button is pressed, GEQ decreases
to its minimum and a message “GEQ MIN” appears.
3. When g(CURSOR LEFT) or G(CURSOR RIGHT) button
is pressed, GEQ is set to flat and a message “GEQ FLAT”
appears.
4. When the VOLUME control knob is turned clockwise even
slightly, the sound volume increases to its maximum and a
message “VOLUME MAX” appears for two seconds, then the
display returns to the original display.
5. When the VOLUME control knob is turned counter-clockwise
even slightly, the sound volume decreases to its minimum and a
message “VOLUME MIN” appears for two seconds, then the
display returns to the original display.
* Check of clock frequency
1. To check the frequency of clock used to run the time in the unit,
the clock output is available at pin 39 (IC 501, MASTER
CONTROL) only during MC test mode.
2. The frequency is 32.768 kHz or so.
* Tuner function
1. In the test mode, the default-preset channel is called even when
the TUNER is selected and an attempt is made to call the preset
channel that has been stored in memory. (It means that the
memory is cleared.)
2. The minimum, center and maximum frequency of each band is
set then.

12
HCD-DX70
* Tape function
1. When a tape is inserted in Deck B and recording is started, the
input source function selects VIDEO automatically.
When CD SYNC/HI-DUB button is pressed during Rec in
function, ALC is turned on.
2. When xbutton is pressed to stop recording, the Tape (Deck)
B is selected and tape is rewound, tape is rewound using m
button, tape is stops at around the record-starting position and
playback of the recordedportionof thetapeisstarted. IfPAUSE
is inserted even once during recording, tape is rewound to the
position around the PAUSE position and is played back.
3. When CD SYNC / HI-DUB button is pressed during playback
of Deck B, either normal speed or high speed can be selected
by this button.
* AMS Test Mode
1. Set TAPE function
2. Select the desired loop by pressing the PLAY MODE button.
Insert a test tape AMS-110A or AMS-120 to Deck A.
3. Press the SPECTRUM button to enter theAMS test mode.
4. After a tape is rewound first, the FF AMS is checked, and the
mechanism is shut off after detecting theAMS signal twice.
5. Then the REWAMS is checked and the mechanism is shut off
after detecting the AMS signal twice.
6. When the check is complete, a message of either OK or NG
appears.
* To return to normal mode again.
1. When you want to exit this mode, press the ?/1button.
2. The cold reset is enforced at the same time.
[VACS ON/OFF Mode]
• This mode is used to switch ON and OFF the VACS (Variable
Attenuation Control System).
Procedure:
Press the ENTER and SPECTRUM buttons simultaneously. The
message “VACS OFF” or “VACS ON” appears.
[CD Service Mode]
• This mode can run the CD sled motor freely. Use this mode, for
instance, when cleaning the pickup.
Procedure:
1. Press ?/1button to turn the set ON.
2. Select the function “CD”.
3. Press three buttons x, ENTER , and OPEN/CLOSE simul-
taneously.
4. The CD service mode is selected.
5. With the CD in stop status, press M button to move the pickup
to outside track, or press m button to inside track.
6. To exit from this mode, perform as follows:
1) Move the pickup to the most inside track.
2) Press ?/1button to turn the set OFF.
Note: • Always move the pickup to most inside track 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.
[CD Ship Mode (Memory Clear) ]
• This mode moves the pickup to the position durable to vibra-
tion. Use this mode when returning the set to the customer after
repair.
Procedure:
1. Press 1/ubutton to turn the set ON.
2. Press three buttons x, ENTER and GAME simultaneously.
3. After the "STANDBY" display blinks six times, a message
“LOCK” is displayed on the fluorescent indicator tube, and the
CD ship mode is set.
[CD Ship Mode (No Memory Clear) ]
• This mode moves the pickup to the position durable to vibra-
tion. Use this mode when returning the set to the customer after
repair.
Procedure:
1. Press 1/ubutton to turn the set ON.
2. Press CD button and 1/ubutton simultaneously.
3. After the "STANDBY" display blinks six times, a message
“LOCK” is displayed on the fluorescent indicator tube, and the
CD ship mode is set.
+
–

13
HCD-DX70
[Aging Mode]
This mode can be used for operation check of CD section and tape deck section.
• If an error occurred:
The aging operation stops and display status.
• If no error occurs:
The aging operation continues repeatedly.
1. Operating method of Aging Mode
Turn on the main power and select “CD” of the function.
1) Set a disc in DISC1 tray. Select ALL DISC CONTINUE, and REPEAT OFF.
2) Load the tapes recording use into the decks A and B respectively.
3) Press three buttons x, ENTER , and
DISC SKIP/EX-CHANGE simultaneously.
4) Aging operations of CD and tape are started at the same time.
5) To exit the aging mode, perform [MC Cold Reset].
3. Aging Mode in CD section
1) Display state
• No error occurs
Note:
[*][*][*][*] : Number of aging operations
Error display
E** s## $$ %%
1234 5
• When the buttons x , ENTER and DISC 1 are pressed simultaneously, number of time of the mechanism error and the NO DISC error
can be checked.
Display: EMC**EDC** **: Number of times of error (Maximum three times)
EMC: Mechanism error
EDC: NO DISC error
• When aging operation is complete, be sure to perform the MC Cold Reset to reset the error history.
D: No disc error
01: FOCUS ERROR
02: GFS ERROR
03: SETUP ERROR
01: NO DISC judgment without chucking retry
02: NO DISC judgment after chucking retry
Status at the time of NO DISC judgment
(High order digits only)
1: STOP
2: SETUP
3: TOC READ
4: ACCESS
5: PLAY BACK
6: PAUSE
7: MANUAL SEARCH (PLAY)
8: MANUAL SEARCH (PAUSE)
AGING[*][*][*][*]
1**
2s
3##
4$$
5%%
M: Mechanism error
Don’t care
High order digits only
D: Stopped during closing due to problems other than mechanism.
E: Stopped during opening due to problems other than mechanism.
C: Stopped during chucking due to problems other than mechanism.
F: Stopped during EX-opening due to problems other than mechanism.
Emergency related errors (High order digits only)
1: Stopped during chuck-up
2: Stopped during chuck-down
3: Time out by EX-OPEN
5: Time out by EX-CLOSE
The error No. 00 indicates the newest error. As the error No. increases, it means the older error.
When you want to retrieve the error history, press the PLAY MODE button in the case of mechanism error.
Or press the REPEAT button in the case of NO DISC error.
Display

14
HCD-DX70
2) Operation during aging mode
In the aging mode, the program is executed in the following
sequence.
(1) The disc tray opens and closes.
(2) The mechanism accesses DISC 2 and makes an attempt to
read TOC. However, since there are no discs, a message
“CD2 NO DISC” appears.
(3) The mechanism accesses DISC 3 and a message “CD3 NO
DISC” appears.
(4) The disc tray turns to select a disc1.
(5) A disc is chucked.
(6) TOC of disc is read.
(7) The pickup accesses to the track 1, and playing 2 seconds.
(8) The pickup accesses to the last track, and playing 2 seconds.
(9) Every time when an aging operation of step 1 to step 8 is
complete, the display “AGING[*][*][*][*]” value increases
as the number of aging operations is counted up.
(10) Returns to step 1.
3. Aging Mode in Tape Deck section
1) Display state
• No error occurs
Display action now
• Error occurred
Display action last time
2) Operation during aging mode
In the aging mode, the program is executed in the following
sequence.
(1) Rewind is executed up to the top of tape A and B.
(2) A tape on FWD side is played for 2 minutes.
(3) FF is executed up to either made for 20 second or the end of
tape.
(4) A tape is reversed, and the tape on REV side is played for 2
minutes.
(5) Rewind is executed up to the top of tape.
(6) Returns to step 2, and repeat steps from 2 to 5.
[Function Change Mode]
* elect either VIDEO or MD of the external FUNCTION input.
Procedure:
1. Turn on the power.
2. Press the two buttons ENTER and ?/1at the same time.
The main power is turned on and the other function of the
previous function is selected and displayed. “MD” or
“VIDEO”.
NO. Display action Action contents Final timing
1 TAPE A AG-1 Rewind the TAPE A, B The top of tape
2 TAPE A AG-2 FWD play the TAPE A 2 minutes playing
3 TAPE A AG-3 F.F. the TAPE A 20 second FF or the end
of tape
4 TAPE A AG-4 REV play the TAPE A 2 minutes playing
5 TAPE A AG-5 Rewind the TAPE A The top of tape
6 TAPE B AG-2 FWD play the TAPE B 2 minutes playing
7 TAPE B AG-3 F.F. the TAPE B 20 second FF or the end
of tape
8 TAPE B AG-4 REV play the TAPE B 2 minutes playing
9 TAPE B AG-5 Rewind the TAPE B The top of tape

15
HCD-DX70
SECTION 4
MECHANICAL ADJUSTMENTS
SECTION 5
ELECTRICAL ADJUSTMENTS
0 dB=0.775 V
DECK SECTION
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 adjust.
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. Switches and controls should be set as follows unless otherwise
specified.
• Test Tape
Record/Playback Head Azimuth Adjustment
Tape Signal Used for
P-4-A100 10 kHz, –10 dB Azimuth Adjustment
WS-48B 3 kHz, 0 dB Tape Speed Adjustment
P-4-L300 315 Hz, 0 dB Level Adjustment
DECK A DECK B
Note: Perform this adjustments for both decks
Procedure:
1. Mode: Playback
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
demagnetizer.
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
set
main board
CN301
Pin 3(L-CH)
Pin 1(R-CH)
main board
CN301
Pin 2(GND)
+
–
level meter
test tape
P-4-A100
(10 kHz, –10 dB)
3.06 N •m to 6.96 N •m
31 to 71 g •cm
(0.43 –0.98 oz •inch)
0.19 N •m to 0.58 N •m
2 to 6 g •cm
(0.02 –0.08 oz •inch)
3.06 N •m to 6.96 N •m
31 to 71 g •cm
(0.43 –0.98 oz •inch)
0.19 N •m to 0.58 N •m
2 to 6 g •cm
(0.02 –0.08 oz •inch)
6.96 N •m to 14.02 N •m
71 to 143 g •cm
(0.98 –1.99 oz •inch)
9.80 N •m
100 g or more
(3.53 oz or more)
9.80 N •m
100 g or more
(3.53 oz or more)
Mode Torque meter
CQ-102C
CQ-102C
CQ-102RC
CQ-102RC
CQ-201B
CQ-403A
CQ-403R
Meter reading
FWD
FWD
back tension
REV
REV
back tension
FF/REW
FWD tension
REV tension

16
HCD-DX70
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
3. Mode: Playback
4. After the adjustments, apply suitable locking compound to the
pats adjusted.
Adjustment Location: Playback Head (Deck A).
Record/Playback/Erase Head (Deck B).
Tape Speed Adjustment DECK B
Note: Start the Tape Speed adjustment as below after setting to the test
mode.
In the test mode, the tape speed is high during pressing the
CD SYNC HI-DUB button.
Procedure:
1. Turn the power switch on.
2. Press the xbutton, ENTER button and DISC 3 button
simultaneously.
(The “TEST MODE”on the fluorescent indicator tube display
while in the test mode.)
To exit from the test mode, press the ?/1button.
Mode: Playback
1. Insert the WS-48B into the deck B.
2. Press the gG button on the deck B.
3. Press the CD SYNC HI-DUB button in playback mode.
Then at HIGH speed mode.
4. Adjust RV1001 on the LEAF SW board do that frequency
counter reads 6,000 ± 30 Hz.
5. Press the CD SYNC HI-DUB button.
Then back to NORMAL speed mode.
6. Adjust RV1002 on the LEAF SW board so that frequency
counter reads 3,000 ± 15 Hz.
Adjustment Location: LEAF SW board
Playback level Adjustment DECK A DECK B
Procedure:
Mode: Playback
Deck A is RV302 (L-CH), Deck B is RV303 (L-CH) so that
adjustment within adjustment level as follows.
Adjustment Level:
CN301 PB level: 334.4 to 748.7 mV (–7.3 to –0.3 dB) level
difference between the channels: within ±0.5 dB
Adjustment Location: MAIN board
Sample Volue of Wow and Flutter: 0.3% or less W. RMS
(WS-48B)
Screw
position
L-CH
peak
within
1dB
Output
level
L-CH
peak
R-CH
peak
within
1dB
Screw
position
R-CH
peak
MAIN
board
CN301
set
test tape
P-4-A100
(10 kHz, –10 dB)
pin 1
oscilloscope
L-CH
R-CH
VH
waveform of oscilloscope
in phase 45°90°135°180°
good wrong
pin 2
pin 3
L
R
+
–
set
test tape
WS-48B
(3 kHz, 0 dB)
main board
CN301 (Pin 3: L-CH)
(
Pin 1: R-CH
)
frequency counte
r
+
–
set
test tape
P-4-L300J
(315 Hz, 0 dB)
main board
CN301 (Pin 3: L-CH)
level meter
forward
reverse

17
HCD-DX70
4. Mode: Record
5. Mode: Playback
6. Confirm playback the signal recorded in step 3 become
adjustable level as follows.
If these levels do not adjustable level, adjustment the RV301
(L-CH) and RV351 (R-CH) on the MAIN board to repeat steps
4 and 5.
Adjustable level:
CN301 PB level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location: MAIN board
[MAIN BOARD] (Component Side)
[LEAF SW BOARD] (Component Side)
REC Bias Adjustment DECK B
Procedure:
INTRODUCTION
When set to the test mode performed in Tape Speed Adjustment,
when the tape is rewound after recording, the “REC memory mode”
which rewinds only the recorded portion and playback is set.
This “REC memory mode”is convenient for performing this
adjustment. During recording, the input signal FUNCTION will
automatically switch to VIDEO.
(If do not operation of stopped from recording complete, and rotette
of shuttle knob then rewind to recording start position.)
1. Press MD/VIDEO button to select VIDEO. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B.
3. After press REC PAUSE/START button, press REC PAUSE/
START button, then recording start.
4. Mode: Record
5. Mode: Playback
6. Confirm playback the signal recorded in step 3 become
adjustable level as follows.
If these levels do not adjustable level, adjustment the RV304
(L-CH) and RV354 (R-CH) on the AUDIO board to repeat steps
4 and 5.
Adjustable level: Playback output of 315 Hz to playback output
of 10 kHz: ±1.0 dB
Adjustment Location: MAIN board
REC Level Adjustment DECK B
Procedure:
INTRODUCTION
When set to the test mode performed in Tape Speed Adjustment,
when the tape is rewound after recording, the “REC memory mode”
which rewinds only the recorded portion and playback is set.
This “REC memory mode”is convenient for performing this
adjustment. During recording, the input signal FUNCTION will
automatically switch to VIDEO.
(If do not operation of stopped from recording complete, and rotate
of shuttle knob then rewind to recording start position.)
1. Press MD/VIDEO button to select VIDEO. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B.
3. After press REC PAUSE/START button, press REC PAUSE/
START button, then recording start.
attenuator
set
MD/VIDEO (AUDIO) IN
1) 315 Hz
2) 10 kHz 50 mV (–23.8 dB)



600 Ω
blank tape
CN-123
AF OSC
+
–
set
recorded
portion
CN301 (Pin 3: L-CH)
(
Pin 1: R-CH
)
level meter
set
MD/VIDEO (AUDIO) IN
315 Hz, 50 mV (–23.8 dB)
blank tape
CS-123
600 Ω
attenuator
AF OSC
+
–
set
recorded
portion
CN301 (Pin 3: L-CH)
(
Pin 1: R-CH
)
level meter
TAPE SPEED
RV1002 RV1001
(NORMAL) (HIGH)
CN1001
         
RV354
CN303
CN301
CN304
RV304
RV301
RV352
RV302
RV353
RV303
RV351
RV11
T11
REC LEVEL (L)
(B)
PB LEVEL (L)
(A)
REC LEVEL (L)
(A) REC LEVEL (R)
(A)
PB LEVEL (L)
(B)
REC LEVEL (R)
(B)
1
3

18
HCD-DX70
FM Tuned Level Adjustment
Procedure:
1. Supply a 28 dB 98 MHz signal from the ANTENNA terminal.
2. Tune the set to 98 MHz.
3. Adjust RV611 to the point (moment) when the TUNED
indicator will change from going off to going on.
Adjustment Location: MAIN board
Null Adjustment
Procedure:
1. Supply a 60 dB 98 MHz signal from the ANTENNA terminal.
2. Tune the set to 98 MHz.
3. Measure voltage between pin 21 of IC 601. Adjust T11 ubtil
the voltage becomes 0 V.
Adjustment Location: MAIN board
Adjustment Location
[MAIN BOARD] Component side
FM RF SSG
75 Ωcoaxial
Carrier frequency : 98 MHz
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 28 dB (at 75 W open)
FM ANTENNA terminal
(TM1)
set
FM RF SSG
75 Ωcoaxial
Carrier frequency : 98 MHz
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 60 dB (at 75 W open)
FM ANTENNA terminal
(TM1)
set
CD SECTION
Note :
1. CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
2. Use LUV-P01 (4-999-032-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10MΩimpedance.
4. 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
Procedure :
1. Connect oscilloscope to TP (FEO).
2. Connect between TP (FEI) and TP (DVC ( 1.65 V) by lead
wire.
3. Turn Power switch on.
4. Load a disc (LUV-P01) and actuate the focus search. (In
consequence of open and close the disc tray, actuate the focus
search)
5. Confirm that the oscilloscope waveform (S-curve) is
symmetrical between A and B. And confirm peak to peak level
within 2 ±0.5 Vp-p.
6. After check, remove the lead wire connected in step 2.
Note : •Try to measure several times to make sure than the ratio
of A : 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.
RF Level Check
Procedure :
1. Connect oscilloscope to TP (RFDC) and (RFAC).
2. Turned Power switch on.
3. Load a disc (LUV-P01) and playback.
4. Confirm that oscilloscope waveform is clear and check RF signal
level is correct or not.
BD board
Oscilloscope
TP(FEO)
TP(DVC)
symmetry
S-curve waveform
within 2 ±0.5Vp-p
A
B
TP(RF)
TP(DVC)
BD board
oscilloscope
RV354
CN303
CN301
CN304
RV304
RV301
RV352
RV302
RV353
RV303
RV351
RV11
T11
FM TUNED LEVEL
NULL
1
3

19
HCD-DX70
Note: Clear RF signal waveform means that the shape “◊”can be
clearly distinguished at the center of the waveform.
RF signal waveform
E-F Balance (1 Track jump) Check
Procedure:
1. Connect oscilloscope to TP (TEO) and TP (DVC) board.
2. Turned Power switch on.
3. Load a disc (LUV-P01) and playback the number nine track.
4. Press the bB button. (Becomes the 1track jump mode.)
5. Confirm that the level B and A (DC voltage) on the oscilloscope
waveform.
1 track jump waveform
6. Adjust RV101 so that A (DC voltage) becomes 0.
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 0.65 ±0.15Vp-p (RFDC)
1.1 ±0.4Vp-p (RFAC)
oscilloscope
BD board
TP (TEO)
TP (DVC)
+
–
DVC
Center of
waveform
B
Symmetry
A (DC voltage)
level=1.0±0.5Vp-p
Checking Location:
[BD BOARD]
DVC
RFAC
RFDC
FEO
TEO

20
HCD-DX70
SECTION 6
DIAGRAMS
Note on Schematic Diagram:
• 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.
•C: panel designation.
Note on Printed Wiring Boards:
•X: parts extracted from the component side.
•: Pattern from the side which enables seeing.
• Indication of transistor.
Note:
The components identified by mark 0or dotted line with
mark 0are critical for safety.
Replace only with part number specified.
•A: B+ Line.
•B: B– Line.
•H: adjustment for repair.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
• Voltages are taken with a VOM (Input impedance 10 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 A)
d: PB (DECK B)
G: REC (DECK B)
J: CD
c: digital out
• Abbreviation
AR : Argentina model
SP : Singapore model
MX : Mexican model
E51 : Chiri and Peru model
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)
B
These are omitted.
CE
Q
C
B
These are omitted.
E
Q