Sony HCD-GRX50 User manual

MICROFILM
SERVICE MANUAL
MINI Hi-Fi COMPONENT SYSTEM
HCD-GRX50/R770/RXD7
Photo: HCD-GRX50
Dolby noise reduction manufactured under license
from Dolby Laboratories Licensing Corporation.
“DOLBY” and the double-D symbol aare trade-
marks of Dolby Laboratories Licensing Corporation.
Canadian Model
HCD-RXD7
AEP Model
HCD-R770/RXD7
UK Model
HCD-R770
E Model
Australian Model
HCD-GRX50
HCD-GRX50/R770/RXD7 are the Ampli-
fier, CD player, Tape Deck and Tuner
section in HMC-GRX50/R770/RXD7.
SPECIFICATIONS
Amplifier section
Canadian model:
Continuous RMS power output (reference)
70 + 70 watts
(6 ohms at 1 kHz, 10% THD)
Total harmonic distortion less than 0.07%
(6 ohms at 1 kHz, 45 W)
European and Russian models:
DIN power output (rated) 80 + 80 watts
(8 ohms at 1 kHz, DIN)
Continuous RMS power output (reference)
100 + 100 watts
(8 ohms at 1 kHz, 10% THD)
Music power output (reference) 170 + 170 watts
(6 ohms at 1 kHz, 10% THD)
Other models:
The following measured atAC 120, 220, 240 V 50/60 Hz
DIN power output (rated) 110 + 110 watts
(8 ohms at 1 kHz, DIN)
Continuous RMS power output (reference)
140 + 140 watts
(8 ohms at 1 kHz, 10% THD)
– Continued on next page –
Model Name Using Similar Mechanism NEW
CD Mechanism Type CDM38LH-5BD32L
Base Unit Name BU-5BD32L
Optical Pick-up Name KSS-213D/Q-NP
Model Name Using Similar Mechanism NEW
Tape Transport Mechanism Type TCM-230AWR2
CD
Section
Tape deck
Section

– 2 –
Specifications (continued)
Inputs
MD/VIDEO (AUDIO) IN: voltage 450 mV/250mV,
(phono jacks) impedance 47 kilohms
MIX MIC: (phone jack) sensitivity 1 mV, impedance 10
kilohms
Outputs
MD OUT: voltage 250 mV,
(phono jacks) impedance 1 kilohms
PHONES: accepts headphones of 8 ohms
(stereo phone jack) or more
SPEAKER:
Canadian model: accepts impedance of 6 to 16 ohms
Other models: accepts impedance of 8 to 16 ohms
SUPER WOOFER (GRX50/RXD7: Canadian models):
Voltage 1 V, impedance 1 kilohm
CD player section
System Compact disc and digital audio system
Laser Semiconductor laser (λ=780nm)
Emission duration: continuous
Laser output Max. 44.6 µW*
*This output is the value measured at
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)
Wavelength 780 -790 nm
Signal-to-noise ratio More than 90 dB
Dynamic range More than 90 dB
CD OPTICAL DIGITAL OUT
(Square optical connector jack, rear panel)
Wavelength 600 nm
Output Level -18 dBm
Tape player section
Recording system 4-track 2-channel stereo
Frequency response 40 - 13,000 Hz (±3 dB),
(DOLBY NR OFF) using Sony TYPE I cassette
40 - 14,000 Hz (±3 dB),
using Sony TYPE II cassette
Tuner section
FM stereo, FM/AM superheterodyne tuner
FM tuner section
Tuning range 87.5 - 108.0 MHz
Antenna FM lead antenna
Antenna terminals 75 ohm unbalanced
Intermediate frequency 10.7 MHz
UKV tuner section (3 band (FM-AM-UKV) models only)
Tuning range 65.0 - 74.0 MHz
Stereo Plus
AM tuner section
Tuning range
2 Band type:
Canadian model: 530 - 1,710 kHz
(with the interval set at 10 kHz)
531 - 1,710 kHz
(with the interval set at 9 kHz)
European and Russian models: 531 - 1,602 kHz
(with the interval set at 9 kHz)
Other models: 531 - 1,602 kHz
(with the interval set at 9 kHz)
530 - 1,710 kHz
(with the interval set at 10 kHz)
3 Band type:
Middle Eastern models:
MW: 531 - 1,602 kHz
(with the interval set at 9 kHz)
SW: 5.95 - 17.90 MHz
(with the interval set at 5 kHz)
Other models:
MW: 531 - 1,602 kHz
(with the interval set at 9 kHz)
530 - 1,710 kHz
(with the interval set at 10 kHz)
SW: 5.95 - 17.90 MHz
(with the interval set at 5 kHz)
Antenna AM loop antenna
Antenna terminals External antenna terminal
Intermediate frequency 450 kHz
General
Power requirements
Canadian model: 120 V AC, 60 Hz
European and Russian models: 230 V AC, 50/60 Hz
Mexican model: 120 V AC, 50/60 Hz
Australian model: 230 - 240 V AC, 50/60 Hz
Israel and Thai models: 220 V AC, 50/60 Hz
Other models: 120 V, 220 V, or 230 - 240 V AC,
50/60 Hz
Adjustable with voltage selector
Power consumption
Canadian model: 130 watts
European and Russian models: 165 watts
Other models: 160 watts
Dimensions (w/h/d) Approx. 280 ×340 ×395 mm
(111/8 ×131/2× 155/8in.)
Mass
Canadian model: Approx. 9.2 kg
European and Russian models: Approx. 10.1 kg
Other models: Approx. 10 kg
Supplied accessories: AM loop antenna (1)
Remote Commander (1)
Batteries (2)
FM lead antenna (1)
Speaker cords (2)
Front speaker pads (8)
Design and specifications are subject to change without notice.
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFIÉS PAR UNE MARQUE !
SUR LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE
DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ
DE FONCTIONNEMENT. NE REMPLACER CES COM-
POSANTS QUE PAR DES PIÈCES SONY DONT LES
NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK !OR DOTTED
LINE WITH MARK !ON 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 PUB-
LISHED BY SONY.

– 3 –
1. SERVICING NOTES ............................................... 3
2. GENERAL
Location of Controls ....................................................... 6
Setting the Time .............................................................. 7
3. DISASSEMBLY ......................................................... 8
4. TEST MODE.............................................................. 11
5. MECHANICAL ADJUSTMENTS....................... 14
6. ELECTRICAL ADJUSTMENTS
DECK Section ................................................................. 14
CD Section ...................................................................... 17
7. DIAGRAMS
7-1. Block Diagram – CD SERVO Section – ........................ 19
7-2. Block Diagram – TAPE DECK Section – ...................... 21
7-3. Block Diagram – MAIN Section – ................................. 23
7-4. Block Diagram – DISPLAY/KEY CONTROL/
POWER SUPPLY Section – ........................................... 25
7-5. Note for Printed Wiring Boards and
Schematic Diagrams ....................................................... 27
7-6. Printed Wiring Board – BD Board – .............................. 29
7-7. Schematic Diagram – BD Board – ................................ 31
7-8. Printed Wiring Boards – CD MOTOR Section – .......... 33
7-9. Schematic Diagram – CD MOTOR Section – .............. 35
7-10. Printed Wiring Board –AUDIO Board – ...................... 37
7-11. Schematic Diagram – AUDIO Board – ......................... 39
7-12. Printed Wiring Board – LEAF SW Board –.................. 41
7-13. Schematic Diagram – LEAF SW Board –..................... 41
7-14. Printed Wiring Board – MAIN Board – ........................ 43
7-15. Schematic Diagram – MAIN Board (1/4) – ................. 45
7-16. Schematic Diagram – MAIN Board (2/4) – .................. 47
7-17. Schematic Diagram – MAIN Board (3/4) – .................. 49
7-18. Schematic Diagram – MAIN Board (4/4) – .................. 51
7-19. Printed Wiring Board – PANEL Board – ...................... 53
7-20. Schematic Diagram – PANEL Board – ......................... 55
7-21. Printed Wiring Board – CD SW Board – ...................... 57
7-22. Schematic Diagram – CD SW Board – ......................... 58
7-23. Printed Wiring Boards
– TRANSFORMER Section – ........................................ 61
7-24. Schematic Diagram
– TRANSFORMER Section – ........................................ 63
7-25. IC Pin Function Description ........................................... 67
8. EXPLODED VIEWS ................................................ 73
9. ELECTRICAL PARTS LIST ............................... 82
TABLE OF CONTENTS
The laser diode in the optical pick-up block may suffer electro-
static 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 emis-
sion, observe from more than 30 cm away from the objective lens.
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.
Flexible Circuit Board Repairing
• Keep the temperature of the soldering iron around 270 ˚C dur-
ing 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
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.
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.
The following caution label is located inside the unit.
CAUTION : INVISIBLE LASER RADIATION WHEN OPEN AND
INTERLOCKS DEFEATED. AVOID EXPOSURE TO BEAM.
ADVARSEL : USYNLIG LASERSTRÅLING VED ÅBNING NÅR
SIKKERHEDSAFBRYDERE ER UDE AF FUNKTION. UNDGÅ UDSAETTELSE
FOR STRÅLING.
VORSICHT : UNSICHTBARE LASERSTRAHLUNG, WENN
ABDECKUNG GEÖFFNET UND SICHEREITSVERRIEGELUNG
ÜBERBRÜCKT. NICHT DEM STRAHL AUSSETZEN.
VARO ! :AVATTAESSA JA SUOJALUKITUS OHITETTAESSA OLET ALT-
TIINA NÄKYMÄTTÖMÄLLE LASERSÄTEILYLLE. ÄLÄ KATSO SÄTEESEEN.
VARNING : OSYNLING LASERSTRÅLING NÄR DENNA DEL ÄR ÖPPNAD
OCH SPÄRREN ÄR URKOPPLAD.BETRAKTA EJ STRÅLEN.
ADVERSEL : USYNLIG LASERSTRÅLING NÅR DEKSEL ÅPNES OG
SIKKERHEDSLÅS BRYTES. UNNGÅ EKSPONERING FOR STRÅLEN.
VIGYAZAT ! :A BURKOLAT NYITÁSAKOR LÁTHATATLAN LÉZERSU-
GÁRVESZÉLY
! KERÜLJE A BESUGÁRZÁST !
SECTION 1
SERVICING NOTES

– 4 –
MODEL PART No.
Argentine model 4-214-442-0π
Israel and Thai models 4-214-442-6π
120 V ACArea in E model 4-215-168-0π
Canadian model 4-215-168-1π
R770: AEP, UK, German and 4-215-168-2π
North European models
RXD7: CIS model 4-215-168-3π
R770: CIS model 4-215-168-4π
RXD7: AEP, German and 4-215-168-5π
North European models
240 V AC Area in E model 4-215-168-6π
Saudi Arabia model 4-215-168-7π
Singapore model 4-215-168-8π
Mexican model 4-215-168-9π
Australian model 4-220-083-0π
Taiwan model 4-220-083-1π
Korean model 4-220-083-2π
PART No.
MODEL IDENTIFICATION
– Rear Panel –

– 5 –
HOW TO OPEN THE DISC TRAY WHEN POWER SWITCH TURNS OFF.
1 Remove the Case.
3 Pull-out the disc tray.
2 Turn the cam to the
direction of arrow.
NOTE FOR INSTALLATION (ROTARY ENCODER)
BU cam
Groove Section A
Note:When attaching the Base unit, Insert th
e
section A into the groove of BU cam.
Note:When attaching the BU cam,
engage the Rotary encoder
switch as shown in the figure.

– 6 –
SECTION 2
GENERAL This section is extracted from
instruction manual.
LOCATION OF CONTOROLS
– Front Panel –
– Rear Panel –
123
5
4
6
8
1CD DIGITAL OUT terminal
2VIDEO (AUDIO) IN jack
3FM COAXIAL ANTENNA terminal
(R770/RXD7:AEP models)
FM ANTENNA terminal
(GRX50/RXD7: Canadian models)
4MD IN/OUT jack
5SUPER WOOFER jack
(GRX50/RXD7: Canadian models)
6SPEAKER terminal
7AM ANTENNA terminal
8VOLTAGE SELECTOR switch
(GRX50: 120 V AC Area in E, 240 V AC Area in E, Saudi
Arabia, Singapore, Taiwan, Argentine models)
7

– 7 –

– 8 –
CASE
LOADING PANEL ASS’Y
Note: Follow the disassembly procedure in the numerical order given.
SECTION 3
DISASSEMBLY
3 two screws
(case 3TP2) (3
× 8)
2 screw
(case 3TP2) (3
× 12)
1 three screws
(BVTP3
× 8)
6 case
2 screw
(case 3TP2) (3
× 12)
3 two screws
(case 3TP2) (3
× 8)
5
4
4
3 loading panel ass’y
2 Pull-out
the disc tray.
1 Turn the cam-in the
direction of the arrow
A .
A

– 9 –
FRONT PANEL SECTION
CD MECHANISM DECK SECTION (CDM38LH-5BD32L)
4 screw
(BVTT2.6
× 5
)
4 screw
(BVTT2.6
× 5)
6 screw
(BVTT3
× 10)
9 front panel section
6 screw
(BVTP3
× 10)
7 three screws
(BVTT3
× 6)
5 lug
5 lug
3 wire (flat type)
(15 core) (CN303)
1 wire (flat type) (17 core)
(CN304)
2 wire (flat type)
(23 core) (CN501)
1 screw
(BVTP3
× 10)
2 two screws
(BVTP3
× 8)
4 two connectors
(CN392, 393)
5 wire (flat type) (19 core)
(CN391)
1 screw
(BVTP3
× 10)
3 Remove the CD mechanism
deck (CDM38LH-5BD32L)
in the direction of arrows
A – B .
B
A

– 10 –
TAPE MECHANISM DECK SECTION (TCM-230AWR2)
MAIN BOARD
1 Push the cassette lid.
4 tape mechanism deck section
(TCM-230AWR2)
1 Push the cassette lid.
2 Open two
cassette lids.
3 two screws
(BVTP2.6
× 8)
3 three screws
(BVTP2.6
× 8)
6 five screws
(BVTP3
× 8)
5 two screws
(BVTP3
× 8)
8 connector
(CN403)
(EXCEPT Canadian)
4 two screws
(BVTP3
× 8)
3 connector
(CN953) (GRX50)
2 connector
(CN952)
7 Remove the MAIN board
in the direction of the arrow.
1 wire (flat type)
13 core: EXCEPT AEP, UK, Singapore, Taiwan
15 core: AEP, UK, Singapore, Taiwan
(CN371)
(
)

– 11 –
SECTION 4
TEST MODE
[MC 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. Turn the power ON or set to the DEMO mode.
2. Press three buttons of p, [ENTER/NEXT], and 1/usimulta-
neously.
3. The set is reset, and displays “COLD RESET”, then becomes
DEMO mode.
[MC 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. Turn the power ON or set to the DEMO mode.
2. Press three buttons of p, [ENTER/NEXT], and [DISC1] si-
multaneously.
3. The set is reset, and becomes standby state.
[Change-over the AMTuning Interval]
(EXCEPT AEP, UK, and Saudi Arabia models)
• The AM tuning interval can be changed over 9 kHz or 10 kHz.
Procedure:
1. Press the 1/ubutton to turn the power ON.
2. Select the function “TUNER”, and press the [TUNER/BAND]
button to select the BAND “AM”.
3. Press the 1/ubutton to turn the power OFF.
4. Press the [ENTER/NEXT] and 1/ubuttons simultaneously,
and the display on the fluorescent indicator tube changes to
“AM 9 k STEP” or “AM 10 k STEP”, and thus the tuning
interval is changed over.
[CD Delivery 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 1/ubutton to turn the power ON.
2. Press the [LOOP] and 1/ubuttons simultaneously.
3. A message “LOCK” is displayed on the fluorescent indicator
tube, and the CD delivery mode is set.
[LED and Fluorescent IndicatorTube All Lit, Key Check
Mode]
Procedure:
1. Press three buttons of p, [ENTER/NEXT], and [DISC2] si-
multaneously.
2. LEDs and fluorescent indicator tube are all turned on.
Press the [DISC2] button, and the key check mode is acti-
vated.
3. In the key check mode, the fluorescent indicator tube displays
“K 0 J0 V0”. Each time a button is pressed, “K” value in-
creases. However, once a button is pressed, it is no longer taken
into account.
“J” value increases like 1, 2, 3 ... if turn the JOG dial clock-
wise, or it decreases like 0, 9, 8 ... if turn the JOG dial counter-
clockwise.
“V” value increases like 1, 2, 3 ... if turn the [VOLUME] dial
clockwise, or it decreases like 0, 9, 8 ... if turn the JOG dial
counterclockwise.
4. To exit from this mode, press three buttons in the same man-
ner as step 1, or disconnect the power cord.
[CD Service Mode]
• This mode can run the CD sled motor optionally. Use this mode,
for instance, when cleaning the optical pick-up.
Procedure:
1. Press the 1/ubutton to turn the power ON.
2. Select the function “CD”.
3. Press three buttons of p, [ENTER/NEXT], and §simulta-
neously.
4. Set to the Sled Servo mode.
5. With the CD in stop status, turn the JOG dial clockwise to
move the optical pick-up to outside track, or turn it counter-
clockwise to inside track.
6. To exit from this mode, perform as follows.
1) Move the optical pick-up to the most inside track.
2) Disconnect the power cord.
Notes: • Always move the optical pick-up 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.

– 12 –
[Aging Mode]
This mode can be used for operation check of CD section and tape
deck section.
CD section and tape deck section work in parallel.
• If an error occurred:
The aging operation stops only an error occurred sections and
display then status.
• If no error occurs:
The aging operation continues repeatedly.
Procedure:
1. Set disc in DISC1 tray.
2. Load the tapes into the decks A and B respectively.
3. Press the [PLAYMODE] button to set the “ALL DISCS” mode,
and press the [REPEAT] button to “REPEAT” off.
4. Press the [FUNCTION] button to select the function “CD”.
5. Press three buttons of p, [ENTER/NEXT], and [DISCSKIP/
EX-CHANGE] simultaneously.
6. The aging mode is activated, if the indicator of disc tray num-
ber on the fluorescent indicator tube is blinking.
7. To exit from the aging mode, press the 1/ubutton to turn the
power OFF and operate the cold reset. (Refer to the “MC Cold
Reset”)
1. Display at the Aging Mode
• Display operating state of CD section and tape deck section al-
ternately.
• If an error occurred, stop display which that section.
2. CD Section
• Display at the aging mode is the same as the normal operation.
• The sequence during the aging mode is following as below.
Aging mode sequence (CD section) :
Turn the disc tray
Disc1 chucking
TOC read
Play track1 for 2 seconds
Play last track for 2 seconds
• Display at an error occurred
1) Display of the error count
(1) Press three buttons of p, [ENTER/NEXT], and [CDSYNC]
simultaneously.
(2) Display of the error count following as below.
Display
EMC**EDC**
Notes:
EMC**: The number of mechanical error.
EDC**: The number of no disc error after chucking the disc.
2) Display of mechanical error
Display
E**M##$$&&
Notes:
**: The number of mechanical error.(“00” is latest one)
(Press the [PLAYMODE] button to changes next error display)
## : Not used.
$$ : Loading error. (Second figure is not used)
D: The error in the midst of close at the except mechanical trouble.
E : The error in the midst of open at the except mechanical trouble.
C : The error in the midst of chuck up at the except mechanical
trouble.
F : The error in the midst of EX-open at the except mechanical
trouble.
&&: Loading error. (Second figure in not used)
1:The error in the midst of chuck up.
2:The error in the midst of chuck down.
3:Time up of EX-open
4:Time up of EX-close.
3) Display of no disc error
Display
E**D##$$&&
Notes:
**: The number of mechanical error.(“00” is latest one)
(Press the [REPEAT] button to changes next error display)
##: 01:Focus error
02:GFS error
03:Set up error
$$: 00:No disc error when does not chucking retry.
02:No disc error when chucking retry to completion.
&&: The state when judged no disc error. (Second figure is not used)
1:Stop
2:Set up
3:TOC read
4:Access
5:Play
6:Pause
7:Manual search (Play)
8:Manual search (Pause)

– 13 –
3. Tape Deck Section
• The sequence during the aging mode is following as below.
• If an error occurred, stop display that step.
Aging mode sequence (Tape deck section) :
Rewind the tape A and B
“TAPE A AG-1”
Shut off
FWD play the tape A
“TAPE A AG-2”
2 minutes
Fast forward the tape A
“TAPE A AG-3”
Shut off or 20 seconds
REV play the tape A
“TAPE A AG-4”
2 minutes
Rewind the tape A
“TAPE A AG-5”
Shut off
FWD play the tape B
“TAPE B AG-2”
2 minutes
Fast forward the tape B
“TAPE B AG-3”
Shut off or 20 seconds
REV play the tape B
“TAPE A AG-4”
2 minutes
Rewind the tape B
“TAPE B AG-5”
Shut off
Note: “TAPE *AG-*” is display of each step.

– 14 –
1. Demagnetize the record/playback head with a head demagne-
tizer.
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 ad-
justment 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 other-
wise specified.
8. Set to the DOLBY NR OFF.
9. Set to the test mode.
(1) Press the 1/ubutton to turn the power ON.
(2) Select the function “TAPE A or B”.
(3) Press the button of p, [ENTER/NEXT], and [DISC3]
simultaneously, to set the tape deck test mode and blink
the indicator of disc tray number on the fluorescent indi-
cator tube.
(4) To exit from the test mode, press the 1/ubutton.
• Test Tape
Record/Playback Head Azimuth Adjustment
Note: Perform this adjustments for both decks
Procedure:
1. Mode: Playback
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
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
(0.03 – 0.08 oz • inch)
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
(0.03 – 0.08 oz • inch)
71 to 143 g • cm
(0.99 – 1.99 oz • inch)
100 g or more
(3.53 oz or more)
100 g or more
(3.53 oz or more)
SECTION 6
ELECTRICAL ADJUSTMENTS
SECTION 5
MECHANICAL ADJUSTMENTS
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 demagne-
tizer.
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 sup-
ply voltage unless otherwise noted.
Torque Measurement
Mode
FWD
Torque meter
CQ-102C
Meter reading
FWD
back tension
REV
REV
back tension
FF/REW
FWD tension
REV tension
CQ-102C
CQ-102RC
CQ-102RC
CQ-201B
CQ-403A
CQ-403R
0 dB=0.775 V
DECK SECTION
DECK A DECK B
set
main board
MD OUT jack (J101)
L-CH, R-CH
+
–
level mete
r
test tape
P-4-A100
(10 kHz, –10 dB)

– 15 –
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)
R-CH
oscilloscope
L-CH
R-CH
VH
waveform of oscilloscope
in phase 45 ° 90 ° 135 ° 180 °
good wrong
main board
MD OUT jack (J101)
L-CH
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. Repeat step 1 to 3 in playback (REV) mode.
5. 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
Mode: Playback
1. Insert the WS-48B into the deck B.
2. Press the (button on the deck B.
3. Press the [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 ± 180 Hz.
5. Press the [HI-DUB] button.
Then back to NORMAL speed mode.
6. Adjust RV1002 on the LEAF SW board so that frequency
counter reads 3,000 ± 90 Hz.
Adjustment Location: LEAF SW board
Sample value of Wow and Flutter: 0.3% or less W.RMS (JIS)
(WS-48B)
Playback level Adjustment DECK A DECK B
Procedure:
Mode: Playback
Deck A is RV311 (L-CH) and RV411 (R-CH), Deck B is RV301
(L-CH) and RV401 (R-CH) so that adjustment within adjustment
level as follows.
Adjustment Level:
J101 PB level: 301.5 to 338.3 mV (–8.2 to –7.2 dB) level
difference between the channels: within ±0.5 dB
Adjustment Location: AUDIO board
forward
reverse
+
–
set
test tape
WS-48B
(3 kHz, 0 dB)
main board
MD OUT jack (J101)
L-CH, R-CH
frequency counter
+
–
set
test tape
P-4-L300
(315 Hz, 0 dB)
main board
MD OUT jack (J101)
L-CH, R-CH
level meter

– 16 –
REC Bias Adjustment DECK B
Procedure:
1. Mode: Record
FUNCTION: VIDEO
2. Mode: Playback
3. Confirm playback the signal recorded in step 1 become speci-
fication values as follows.
If these values are out of specification values, adjust the RV341
(L-CH) and RV441 (R-CH) on the AUDIO board to repeat
steps 1and 2.
Specification values: Playback output of 315 Hz to playback
output of 10 kHz: ± 0.5 dB
Adjustment Location: AUDIO board
REC Level Adjustment DECK B
Procedure:
1. Mode: Record
FUNCTION: VIDEO
2. Mode: Playback
3. Confirm playback the signal recorded in step 1 become speci-
fication values as follows.
If these values are out of specification values, adjust the RV301
(L-CH) and RV351 (R-CH) on the MAIN board to repeat steps
1 and 2.
Specification values:
J101 PB level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location: MAIN board
– MAIN BOARD (Conductor Side) –
– AUDIO BOARD (Component Side) –
– LEAF SW BOARD (Component Side) –
attenuator
set
main board
VIDEO (AUDIO) IN jack (J101)
L-CH, R-CH
1) 315 Hz
2) 10 kHz 50 mV (–23.8 dB)



600 Ω
blank tape
CN-123
AF OSC
+
–
set
recorded
portion
main board
MD OUT jack (J101)
L-CH, R-CH
level meter
set
main board
VIDEO (AUDIO) IN jack (J101)
L-CH, R-CH
315 Hz, 50 mV (–23.8 dB) blank tape
CS-123
600
Ω
attenuator
AF OSC
+
–
set
recorded
portion
main board
MD OUT jack (J101)
L-CH, R-CH
level meter
RV301
L
RV351
R
IC301 REC LEVEL
J101
VIDEO (AUDIO) IN
(L/R)
MD OUT
(L/R)
RV401
RV301 RV341 RV311 RV411
IC602 CN601
LRRL
     
RV441
PB LEVEL
– DECK B –
REC BIAS
LR
  
PB LEVEL
– DECK A –
TAPE SPEED
RV1002 RV1001
(NORMAL) (HIGH)
CN1001
         

– 17 –
Note:
1. CD Block is basically designed to operate without adjustment. There-
fore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10 MΩimpedance.
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 (FE).
2. Connect between TP (FE1) and TP (VC) by lead wire.
3. Connect between TP (AGCCON) and TP (GND) by lead wire.
4. Turn the power ON.
5. Load a disc (YEDS-18) and actuate the focus search. (In con-
sequence of open and close the disc tray, actuate the focus
search)
6. Cofirm that the oscilloscope waveform (S-curve) is symmetri-
cal between A and B. And confirm peak to peak level within
4 ± 1 Vp-p.
S-curve waveform
7. After check, remove the lead wire connected in step 2 and 3.
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.
RF Level Check
Procedure:
1. Connect oscilloscope to TP (RF).
2. Connect between TP (AGCCON) and TP (GND) by lead wire.
3. Turn the power ON.
4. Load a disc (YEDS-18) and playback.
5. Confirm that the oscilloscope waveform is clear and check RF
signal level is correct or not.
6. After check, remove the lead wire connected in step 2.
Note: Clear RF signal waveform means that the shape “≈” can be clearly
distinguished at the center of the waveform.
CD SECTION
+
–
BD board
TP (FE)
TP (VC)
oscilloscope
A
B
symmetry
within 4
± 1 Vp-p
+
–
BD board
TP (RF)
TP (VC)
oscilloscope
VOLT/DIV: 200 m
V
TIME/DIV: 500 ns
level:
1.45
± 0.3 Vp-p
E-F Balance (1Track Jump) Check
Procedure :
1. Connect oscilloscpe to TP (TE) and TP (VC).
2. Turn the power ON.
3. Load a disc (YEDS-18) and playback the number five track.
4. Press the ^(CD) button. (Becomes the 1 track jump mode)
5. Confirm that the level B and A (DC voltage) on the oscillo-
scope waveform.
1 track jump waveform
Specified level: ×100 = less than ± 22%
6. After check, remove the lead wire connected in step 1.
A
B
+
–
BD board
TP (TE)
TP (VC)
oscilloscope
A (DC voltage
)
center of
waveform
B
0V
level = 1.3
± 0.6 Vp-p symmetry

– 18 –
Checking Location:
– BD BOARD (Side B) –
TP (VC)
TP (FE)
TP (FE1)
TP (TE)
TP (RF)
TP
(AGCCON)
TP (GND)
IC102
IC103

HCD-GRX50/R770/RXD7
– 19 – – 20 –
SECTION 7
DIAGRAMS
7-1. BLOCK DIAGRAM – CD SERVO Section –
SQSO SQCK
A/D
CONVERTER
CH1OUTF
CH1OUTR
5
4
7
2
1
5
10
6
6
7
8
16
14
13
10
11
22
4
3
51
49
48
43
24
41
40 39
64 15
28
29
30
31
32
33
24
25
23
5
6
2
3
17
18
15
16
E
B
C
D
A
CD D+5V
F
DETECTOR
A
B
C
D
RF
SUMMING
AMP
FOCUS
ERROR AMP
RF EQ
AMP
TRACKING
ERROR AMP
RFO
FE
RF AMP,
FOCUS/TRACKING ERROR AMP
IC103
TE
E
FF I-V AMP
E I-V AMP
AUTOMATIC
POWER
CONTROL
Q101
APC LD
AMP APC PD
AMP
LD
LD
PD
LASER DIODE
RFAC
ASYO
ASYI
ASYMMETRY
CORRECTION DIGITAL
PLL
DIGITAL SIGNAL PROCESSOR,
DIGITAL FILTER, D/A CONVERTER
IC101 (1/2)
DATA
XLAT
CLOK
14 5 6
MDP
26 78
XLON
3
XRST
DIGITAL
CLV
D/A
INTERFACE
SE
TE
FE
RFDC
FOCUS/TRACKING/SLED
SERVO DSP
FOCUS/TRACKING/SLED
PWM GENERATOR
SFDR
CH3FIN
CH4SIN
CH3RIN
CH3OUTF
CH3OUTR
CH2FIN
CH2RIN
CH1FIN
CH1RIN
20
MUTE
SRDR
TFDR
TRDR
FFDR
FRDR
S101
(LIMIT)
EMPH
WFCK GFS
MIRR/DFCT/
FOK
DETECTOR
SERVO AUTO
SEQUENCER SERVO
INTERFACE
CPU INTERFACE
18
63
62
61
19
SENS
20
35
57
58
37
56
19
SCOR
SQ-DATA
SQ-CLK
CD-DATA
XLT
CD-CLK
SENSE
SCOR
1 2
32
33
SCLK
COUT
9 21
SSTP
27
FOK
22
23
MIRR
DFCT
TO SERVO INTERFACE
CH4OUTF
CH4OUTR
M101
(SPINDLE) MOTOR
DRIVE
MOTOR
DRIVE
COIL
DRIVE
CH2OUTF
CH2OUTR
COIL
DRIVE
M
M
M102
(SLED)
05
FOCUS/TRACKING COIL DRIVE,
SPINDLE/SLED MOTOR DRIVE
IC102
2-AXIS
DEVICE
(TRACKING)
(FOCUS)
DIGITAL SERVO
PROCESSOR
IC101 (2/2)
OPTICAL PICK-UP
(KSS-213D/Q-NP)
LDON
21
HOLD SW
PD
I-V AMP
12
11
13
14
54 56 53 55
FILTER
FILO
PCO
CLTV
FILI
EFM
DEMODULATOR
SERIAL
IN
INTERFACE
DIGITAL
FILTER,
NOISE SHAPER
PWM
&
INTEGRATOR BUFFER
CLOCK
GENERATOR
OPTICAL
TRANSCEIVER
IC381
IC381
CD DIGITALOUT
OPTICAL
TIMING
LOGIC
DIGITAL
OUT
INTERNAL BUS
16K
RAM
ERROR
CORRECTOR
SUBCODE
PROCESSOR
60
HOLD
59 XRST
XTAI
X101
16.9344MHz
AIN1
AIN2 R-CH
CD-L
AOUT1
AOUT2
TO MIRR/DFCT/
FOK DETECTOR
PCMD
BCK
LRCK
C2PO
DOUT
66
XTAO 67
70
77
LOUT1
LOUT2
72
75
71
76
•SIGNAL PATH
: CD PLAY (ANALOG OUT)
: CD PLAY (DIGITAL OUT)
SYSTEM CONTROLLER
(CD MECHANISM CONTROL)
IC501 (1/4)
When the optical pick-up
is inner position.
ON :
DISC TRAY
ADDRESS DETECT
(Page 23)
A
TBL-L
TBL-R
M
3
6
7
2
MOTOR
DRIVE
DISC TRAY TURN MOTOR DRIVE
IC701
OUT1
OUT2
IN1
IN2 M701
(DISC TRAY TURN)
LEVEL SHIFT
Q701
DISC IN DETECT
SENSOR
IC703
DISC TRAY SENSOR
IC702
ROTARY
ENCODER
S811
DISC-SENS
OUT-OPEN
S801
(OPEN/CLOSE DET)
ENC1
ENC2
ENC3
60
TBL-SENS 61
470
CLOSE
OPEN
71
69
68 2 3
63
65
LOAD-OUT
LOAD-IN
M
10
2
7
4
MOTOR
DRIVE
DISC TRAY SLIDE MOTOR DRIVE
IC801
OUT1
OUT2
FIN
RIN M801
(DISC TRAY SLIDE)
66
67

HCD-GRX50/R770/RXD7
– 21 – – 22 –
7-2. BLOCK DIAGRAM – TAPE DECK Section –
PB EQ AMP
(DECK A)
IC611
PB LEVEL (L)
(DECK A)
REC-L
PB-L
CAPSTAN MOTOR
CONTROL SWITCH
Q1001
CAPSTAN
MOTOR DRIVE
Q336 – 343
1
B
(Page 23)
(Page 24)
L-CH
R-CH R-CH
HP101
(PLAYBACK)
PB EQ AMP
(DECK B)
IC601
L-CH
R-CH R-CH
05
R-CH
R-CH
HRPE101 (1/2)
(RECORD/PLAYBACK)
ALC REC
EQ AMP
AMS
CIRCUIT
DOLBY NR
AMP
CIRCUIT
BIAS
CONTROL
CIRCUIT
DOLBY PASS
R-CH
L.P.F.
BUFFER
Q335
M
M1
(CAPSTAN)
HRPE101 (2/2)
(ERASE)
BIAS OSC
T621
B+
(A+7V)
R-CH
3
46
28 43
36
40
35 34 39
26
77
19 15 16 18 20 22 23 24 2517
85 84 83 82 81 80 79 78
31
33
32
+
48
4
2
RV311
PB LEVEL (L)
(DECK B)
RV301
TAPE SPEED
(NORMAL)
RV1002
TAPE SPEED
(HIGH)
RV1001
REC LEVEL (L)
(DECK B)
RV301
REC BIAS (R)
(DECK B)
RV441
REC BIAS (L)
(DECK B)
BIAS OSC
Q621, 622
REC BIAS
SWITCH
Q623
ROTATION
DETECT SENSOR
(DECK A)
IC1001
RV341
BIAS
TRAP
C331, L331
REC/PB SWITCHING
IC602
SYSTEM CONTROLLER
IC501 (2/4)
DECK PROCESS
DECK A/B SELECT, PB/REC EQ AMP,
DOLBY NR AMP, ALC, AMS
IC301
AIN (L)
BIN (L)
MAOUT
PB OUT (L)
EQ OUT
(L)
MSIN
MSOUT
BIAS ON/OFF
70
120
BIAS (N)
BIAS (C)
BIAS (M)
S1004
A 120/70
B NORM/CROM ALC ON/OFF
PB A/B
NORM/HIGH
NR ON/OFF
RM ON/OFF
REC/PB/PASS
LM ON/OFF
(DECK A 120/70)
88
S1003
(DECK A HALF)
S1001
(DECK A PLAY) S1002 (DECK B PLAY)
S1008
(DECK B 120/70)
27
REC OUT (L)
ROUT (L)
RIN (L)
ALC (L)
EQ IN (L) ALC IN (L)
44 38
100
AMS-IN
91
A-SHUT
ROTATION
DETECT SENSOR
(DECK B)
IC1002
90
B-SHUT
TRIGGER
PLUNGER DRIVE
(DECK A)
Q333, 334
73
A-TRG
TC-MUTE
R/P-PASS
NR-ON/OFF
REC-MUTE
BIAS
EQ-H/N
PB-A/B
ALC-ON/OFF
TC-RELAY
A-PLAY-SW B-PLAY-SW A-HALF
89
S1006
(DECK B HALF)
S1009
(DECK B REC)
S1005
(DECK A REC)
B-HALF
TRIGGER PLUNGER
DECK A
TRIGGER
PLUNGER DRIVE
(DECK B)
Q331, 332
72
B-TRG
76
74
75
CAP-M-H/L
CAPM-CNT2
CAPM-CNT1
TRIGGER PLUNGER
DECK B
87 86
C
• SIGNAL PATH
: PLAYBACK (DECK A)
: PLAYBACK (DECK B)
: RECORD
D+5V