Sony HCD-VR90AV User manual

HCD-VR90AV
E Model SERVICE MANUAL
COMPACT Hi-Fi STEREO SYSTEM
MICROFILM
SPECIFICATIONS
HCD-VR90AV is the tuner, deck, CD and ampli-
fier section in LBT-VR90AV.
Model Name Using Similar Mechanism HCD-VR50/VR70
CD Mechanism Type CDM37L-5BD34L
Base Unit Name BU-5BD34L
Optical Pick-up Name KSS-213D/Q-NP
Model Name Using Similar Mechanism NEW
Tape Transport Mechanism Type TCM-230AWR2/230PWR2
CD
Section
Tape deck
Section
Amplifier section
Front Speaker:
The following measured atAC 120/220/240V, 50/60Hz
DIN power output (Rated) 130 + 130W
(6 Ωat 1 kHz, DIN)
Continuous RMS power output (Reference)
160 +160W
(6 Ωat 1 kHz, 10% THD)
Center Speaker:
DIN power output (Rated) 30W
(8 Ωat 1 kHz, DIN)
Continuous RMS power output (Reference)
40W
(8 Ωat 1 kHz, 10% THD)
Rear Speaker:
DIN power output (Rated) 30 + 30W
(8 Ωat 1 kHz, DIN)
Continuous RMS power output (Reference)
40 + 40W
(8 Ωat 1 kHz, 10% THD)
Inputs
PHONO IN (phono jacks): sensitivity 3mV,
impedance 47k Ω
MIX MIC (phone jack): sensitivity 1mV,
impedance 10k Ω
VIDEO1 IN (phono jacks): sensitivity 250mV,
impedance 47k Ω
VIDEO2 IN (phono jacks): sensitivity 250mV,
impedance 47k Ω
MD IN (phono jacks): sensitivity 450mV,
impedance 47k Ω
DVD INPUT
FRONT (phono jacks): sensitivity 450mV,
impedance 47k Ω
REAR (phono jacks): sensitivity 450mV,
impedance 47k Ω
CENTER (phono jacks): sensitivity 450mV,
impedance 47k Ω
WOOFER (phono jacks): sensitivity 450mV,
impedance 47k Ω
Outputs
PHONES (stereo phone jack):accepts headphones of
8 Ωor more
VIDEO OUT (phono jack): voltage 250mV,
impedance 1k Ω
MD OUT (phono jacks): voltage 250mV,
impedance 1k Ω
WOOFER OUT (phono jack):voltage 1V,
impedance 1k Ω
FRONT SPEAKER: accepts impedance of 8
to 16 Ω
CENTER SPEAKER: accepts impedance of 8
to 16 Ω
REAR SPEAKER: accepts impedance of 8
to 16 Ω
— Continued on next page —
Video section
Inputs
VIDEO1 IN (phono jacks): 1Vp-p, 75 Ω
VIDEO2 IN (phono jacks): 1Vp-p, 75 Ω
DVD INPUT VIDEO (phono jacks):
1Vp-p, 75 Ω
Output
VIDEO OUT (phono jack): 1Vp-p, 75 Ω
S-VIDEO OUT (4-pin/mini-DIN jack):
Y : 1Vp-p, unbalanced,
Sync negative,
C : 0.286 V p-p,
load immpedance
75 Ω

2
VIDEO CD/CD player section
System Compact disc and digital audio and video system
Laser Semiconductor laser
(λ=780nm) Emission
duration: continuous
Laser output Max. 44.6µW*
* This output is the value measured at a distance of
200 mm from the objective lens surface on the Optical
Pick-up Block with 7 mm aperture.
Wave length 780 – 790 nm
Frequency response 2Hz – 20kHz (±0.5dB)
Signal-to-noise ratio More than 90 dB
Dynamic range More than 90 dB
Video color system format
NTSC, PAL
CD DIGITAL OUT
(square optical connector jack, rear panel)
Wave length: 660 nm
Output level: –18dBm
Tape player section
Recording system 4-track 2-channel stereo
Frequency response (DOLBY NR OFF)
40 – 13,000Hz (±3dB),
using a Sony TYPE I
cassette
40 – 14,000Hz (±3dB),
using a Sony TYPE II
cassette
Wow and flutter ±0.15% W.Peak (IEC)
0.1% W.RMS (NAB)
±0.2% W.Peak (DIN)
Tuner section
FM stereo, FM/AM superheterodyne tuner
FM tuner section
Tuning range 87.5 – 108.0 kHz
(100 kHz step)
Antenna FM wire antenna
Antenna terminals 75 Ωunbalanced
Intermediate frequency 10.7 MHz
AM tuner section
Tuning range
Middle Eastern model : 531 – 1,602 kHz
(with the tuning interval set at 9 kHz)
Other models : 531 – 1,602 kHz
(with the tuning interval set at 9 kHz)
530 – 1,710 kHz
(with the tuning interval set at 10 kHz)
Antenna AM loop antenna, External antenna terminals
Intermediate frequency 450 kHz
General
Power requirements
Thai model : 220 V AC, 50/60 Hz
Other models : 120 V, 220V, or 230 – 240V AC, 50/60 Hz
Adjustable with voltage selector
Power consumption 280 W
Dimensions (w/h/d) Approx. 356 ×423 ×446 mm
incl. projecting parts and controls
Mass Approx. 15.0 kg
Supplied accessories AM loop antenna (1)
Remote RM-SV100AVB (1)
R6 (size AA) batteries (2)
FM wire antenna (1)
Speaker cords (2)
Video connecting cable
Design and specifications are subject to change without notice.

3
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK !OR DOTTED LINEWITH
MARK !ON THE SCHEMATIC DIAGRAMS AND INTHE 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.
This appliance is classified as a CLASS 1 LASER product. The
CLASS 1 LASER PRODUCT MARKING is located on the rear
exterior.
The following caution label is located inside the unit.
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
otherthan those specifiedherein mayresultin hazardousradiation
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.
MODEL IDENTIFICATION
— BACK PANEL —
• Abbreviation
IA : Indonesia model
EA : Saudi Arabia model
MY : Malaysia model
SP : Singapore model
TH : Thai model
Parts No.
NOTES ON HANDLINGTHE 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.
LASER DIODE AND FOCUS SEARCH OPERATION
CHECK
Carry out the “S curvecheck” in“CD section adjustment” and check
that the S curve waveform is output four times.
PARTS No. MODEL
4-214-793-0πMY,SP
4-214-793-1πEA
4-214-793-3πIA
4-214-793-4πTH

4
TABLE OF CONTENTS
6-15. Schematic Diagram Deck Section ································ 40
6-16. Printed Wiring Board Deck Section ·····························41
6-17. Printed Wiring Board Power Section ··························· 42
6-18. Schematic Diagram Power (1/2) Section ····················· 43
6-19. Schematic Diagram Power (2/2) Section ····················· 44
6-20. Schematic Diagram Surround Section ························· 45
6-21. Printed Wiring Board Surround Section······················· 45
6-22. Schematic Diagram FL Section···································· 46
6-23. Printed Wiring Board FL Section ·································47
6-24. Schematic Diagram Panel VR Section ························· 48
6-25. Printed Wiring Board Panel VR Section ······················ 49
6-26. Schematic Diagram TC Panel Section ························· 50
6-27. Printed Wiring Board TC Panel Section······················· 51
6-28. Schematic Diagram CD Panel Section ························· 52
6-29. Printed Wiring Board CD Panel Section ······················ 53
6-30. Schematic Diagram CD Motor Section ························ 54
6-31. Printed Wiring Board CD Motor Section ····················· 55
6-32. Schematic Diagram Jack Section ································· 56
6-33. Printed Wiring Board Jack Section ······························ 57
6-34. Schematic Diagram Trans Section ······························· 58
6-35. Printed Wiring Board Trans Section····························· 59
6-36. Schematic Diagram Leaf SW Section ·························· 59
6-37. Printed Wiring Board Leaf SW Section ······················· 59
6-38. IC Block Diagrams ··························································· 60
6-39. IC Pin Functions ······························································· 61
7. EXPLODEDVIEWS
7-1. Case and Back Panel Section ··········································· 69
7-2. Front Panel Section 1 ······················································· 70
7-3. Front Panel Section 2 ······················································· 71
7-4. Chassis Section ································································· 72
7-5. TC Mechanism Section 1 (TCM230AWR2/230PWR2) ·· 73
7-6. TC Mechanism Section 2 (TCM230AWR2/230PWR2) ·· 74
7-7. CD Mechanism Section (CDM37M-5BD32L) ················ 75
7-8. Base Unit Section (BU-5BD32L)····································· 76
8. ELECTRICAL PARTS LIST······································· 77
1. GENERAL ·········································································· 5
2. DISASSEMBLY
2-1. Front Panel ········································································· 7
2-2. Main Board ········································································· 7
2-3. Sub Panel ············································································ 8
2-4. CD-L/CD-R Board and CD Lid Assembly························· 8
2-5. Tape Mechanism Deck and Cassette Lid····························9
2-6. CD Mechanism Deck ························································· 9
2-7. Base Unit ············································································ 9
2-8. Disc Table ········································································· 10
3. SERVICE MODE ···························································· 11
4. MECHANICAL ADJUSTMENTS ····························· 15
5. ELECTRICAL ADJUSTMENTS ······························· 15
6. DIAGRAMS
6-1. Circuit Boards Location ··················································· 19
6-2. Block Diagrams
BD Section ······································································· 20
Video Section ··································································· 21
Deck Section····································································· 22
Main (1/2) Section···························································· 23
Main (2/2) Section···························································· 24
Power Section ··································································· 25
Display Section································································· 26
6-3. Printed Wiring Board BD Section ································ 28
6-4. Schematic Diagram BD Section··································· 29
6-5. Printed Wiring Board Video Section ···························· 30
6-6. Schematic Diagram Video (1/3) Section ······················ 31
6-7. Schematic Diagram Video (2/3) Section ······················ 32
6-8. Schematic Diagram Video (3/3) Section ······················ 33
6-9. Printed Wiring Board Main Section ····························· 34
6-10. Schematic Diagram Main (1/5) Section ······················· 35
6-11. Schematic Diagram Main (2/5) Section ······················· 36
6-12. Schematic Diagram Main (3/5) Section ······················· 37
6-13. Schematic Diagram Main (4/5) Section ······················· 38
6-14. Schematic Diagram Main (5/5) Section ······················· 39

5
SECTION 1
GENERAL
Location of Parts and Controls
11/u (Power) button
2POWER SAVE/DEMO (STANDBY)
button
3DISPLAY button
4SPECTRUM ANALYZER button
5Display window
6GEQ control button
7SYNC BASS button
8SYNC EQ button
9Remote sensor
0TUNING MODE button
!¡ STEREO/MONO button
!™ ENTER/NEXT button
!£ TUNER MEMORY button
!¢ TUNER/BAND button
!∞ TUNING - button
!§ TUNING + button
!¶ FUNCTION button
!• VOLUME knob
!ª PHONES jack
@º ECHO LEVEL knob
@¡ MIC LEVEL knob
@™ MIC 1 jack
@£ MIC 2 jack
@¢ GROOVE button
@∞ SUPER WOOFER button
@§ MODE button
@¶ ª(B Deck) button and indicator
@• ·(B Deck) button and indicator
@ª p(B Deck) button
#º 0(B Deck) button
#¡ )(B Deck) button
#™ P(B Deck) button
#£ rREC (B Deck) button
#¢ HI-SPEED DUB button
#∞ CD SYNCHRO button
#§ PLAY MODE button
#¶ REPEAT button
#• 0(CD) button
#ª )(CD) button
$º ·P (CD) button and indicator
$¡ p(CD) button
$™ DISC SKIP button
$£ =AMS +knob
$¢ VIDEO2 INPUT jacks
$∞ PRO LOGIC button and indicator
$§ DVD 5.1 CH
$¶ KEY CONTROL # button
$• KEY CONTROL b button
$ª EDIT button
%º NON-STOP button and indicator
%¡ FLASH button
%™ LOOP button
%£ NEXT button
%¢ PREV button
%∞ RETURN button
%§ DISC 5 button
%¶ DISC 4 button
%• DISC 3 button
%ª DISC 2 button
^º DISC 1 button
^¡ SELECT button
^™ ACTIVE button
^£ DOLBY NR button
^¢ DIRECTION button
^∞ )(A Deck) button
^§ 0(A Deck) button
^¶ p(A Deck) button
^• ·(A Deck) button
^ª ª(A Deck) button
&º KARAOKE PON/MPX button
&¡ DSP button and indicator
&™ EFFECT button and indicator
&£ ENTER button and indicator
&¢ GEQ CONTROL button
&∞ P. FILE MEMORY
&§ Equalizer indicators
&¶ t/CLOCK SET button
&• SLEEP button
&ª REC button and indicator
*º DAILY button and indicator
• AMS is the abbreviation for Automatic
Music Sensor.
Front Panel
234
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6
This section is extracted
from instruction manual.

7
SECTION 2
DISASSEMBLY
Note : Follow the disassembly procedure in the numerical order given.
2-1. FRONT PANEL
2-2. MAIN BOARD
1 Three flat type wires
(CN303,CN304,CN431)
2 Connector (CN702)
3 Connector (CN452)
4 Connector (CN802)
7 Front panel
5 Screw (BVTP 3x8
)
6 Four screw (BVTP 3x8)
4 Connector (CN412)
5 Flat type wire (CN411)
1 Flat type wire (CN1
)
3 Tuner unit
2 Two screws (BVTP 3x8)
7 Seven screws (BVTP 3x8)
!¡ Fan motor
!™ Power cord
!£ Back panel
8 Five screws (BVTP 3x8)
6 Connector (CN903)
!§ Main board
!¢ Two screws (BVTP 3x8
)
0 Two screws (BVTP 3x8)
9 Four screws (BVTP 3x8)

8
2-3. SUB PANEL
2-4. CD-L/CD-R BOARD AND CD LID ASSEMBLY
3 Open the CD lid assembly
8 Sub panel block
4 Two screws (BTP 2.6x6)
1 Two screws (BVTP 2.6x8)
6 Two screws (BVTP 2.6x8)
7 Three screws (BVTP 2.6x8)
5 Screw (BVTP 3x8)
2 Front input board
9 Two screws (BVTP 2.6x8)
0 Bracket (CD-R2)
!£ CD lid assembly
1 Three screws (BVTP 2.6x8)
7 Three screws
(BVTP 2.6x8)
8 Two screws (BVTP 2.6x8)
9 Bracket (CD-R)
0 CD-R board
2 Three screws
(BVTP 2.6x8)
3 Bracket (CD-L)
4 CD-L board
!™ Torsion spring (CD-L)
Torsion spring (CD-L) Sub panel assembly
Sub panel assembly
CD lid assembly
5 Knob (CD)
6 Nut
!¡ Torsion spring (CD-R)

9
2-5.TAPE MECHANISM DECK AND CASSETTE LID
2-6. CD MECHANISM DECK 2-7. BASE UNIT
5 Cassette lid (B) assembly
(Refer to upper figure)
7 Holder (B) assembly
(Refer to lower figure)
6 Holder (A) assembly
(Refer to lower figure)
4 Cassette lid (A) assembly
(Refer to upper figure)
Cassette lid assembly
Holder assembly
Claw
Claw
Claw
Claw
8 Torsion spring (TC-A)
9 Torsion spring (TC-B)
1 Three screws (BVTP 2.6x8)
2 Three screw
s
(BVTP 2.6x8
)
3 Tape mechanism
Portion B
Portion B
Portion A
Portion A
1 Five screws (BVTP3x8)
2 CD mechanism
deck
3 Base uni
t
1 Yoke fitting
2 Boss

10
2-8. DISCTABLE
Note:
When the disc table is installed, adjust the positions of
roller cam and mark ”as shown in the figure, then set to
the groove of disc table.
A
A
2 Screw (BVTP3X8)
1 Screw (BVTP3X8)
4 Stop screw
5 Disc table
3 Bracket (BU)

11
SECTION 3
SERVICE MODE
About CD-TEXT display
This unit is provided with a simple CD-TEXT display function.
The CD-TEXT contents of 20 tracks are displayed on the fluorescent display tube.
Since the function is simple, some special characters may not be displayed, or may be displayed as other characters.
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. Press three buttons t/CLOCK SET , ENTER , and 1/usimultaneously.
2. “COLD RESET” is displayed on the fluorescent display tube and reset is executed.
CD Delivery Mode
• This mode moves the pick-up to the position durable to vibration. Use this mode when returning the set to the customer after repair.
Procedure:
1. Press 1/ubutton to turn the set ON.
2. Press LOOP button and 1/ubutton simultaneously.
3. Press the 1/ubutton again to turn the set OFF.
4. A message “LOCK” is displayed on the fluorescent indicator tube, and the CD delivery mode is set.
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. Press three buttons t/CLOCK SET , ENTER , and DISC 1 simultaneously.
2. The fluorescent indicator tube becomes blank instantaneously, and the set is reset.
Sled Servo Mode
• This mode can run the CD sled motor freely. Use this mode, for instance, when cleaning the pick-up.
Procedure:
1. Press 1/ubutton to turn the set ON.
2. Press three buttons t/CLOCK SET , ENTER , and DISC 5 simultaneously.
3. The Sled Servo mode is selected, if “CD” is blanking on the fluorescent indicator tube.
4. With the CD in stop status, When )button is pressed, the pick-up moves outside.When 0button is pressed, the pick-up moves
inside.
5. To exit from this mode, perform as follows:
1) Move the pick-up to the most inside track.
2) Execute MC cold reset. (Press the three buttons t/CLOCK SET , ENTER , and 1/ubutton simultaneously.)
Note:
• Always move the 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.
Change-over of AMTuner Step between 9kHz and 10kHz
• A step of AM channels can be changed over between 9kHz and 10kHz.
Procedure:
1. Press 1/ubutton to turn the set ON.
2. Select the function “TUNER”, and press TUNER/BAND button to select the BAND “AM”.
3. Press 1/ubutton to turn the set OFF.
4. Press ENTER and 1/ubuttons simultaneously, and the display of fluorescent indicator tube changes to “AM 9k STEP” or “AM 10k
STEP”, and thus the channel step is changed over.
LED and Fluorescent IndicatorTube All Lit, Key Check Mode
Procedure:
1. Press three buttons t/CLOCK SET , ENTER , and DISC 2 simultaneously.
2. LEDs and fluorescent indicator tube are all turned on.
Press DISC 2 button, and the key check mode is activated.
3. In the key check mode, the fluorescent indicator tube displays“K0V0 J0”. Each time a button is pressed, “K”value increases. However,
once a button is pressed, it is no longer taken into account.
“J” Value increases like 1, 2, 3 ... if rotating =AMS +knob in “+” direction, or it decreases like 0, 9, 8 ... if rotating in “-”
direction.
“V”Value increases like 1, 2, 3 ... if rotating VOLUME knob in “+” direction, or it decreases like 0, 9, 8 ... if rotating in “-” direction.
4. To exit from this mode, press three buttons in the same manner as step 1, or disconnect the power cord.

12
AMSTest Mode
• This mode is used for checking the AMS operations of the tape deck.
JIG
7-819-039-12 Alignment tape, AMS-110A
Procedure:
1. Press the 1/ubutton to turn the set ON.
2. Set the tape (AMS-110A).
3. Press the three buttons t/CLOCK SET , ENTER , and DISC 3 button simultaneously.
4. “TEST MODE” is displayed on the fluorescent display tube. At the same time, the VOLUME indicator blinks.
5. Press the FUNCTION button and switch the function to the deck with the tape (AMS-110A).
6. Press the CD SYNCHRO button. “AMS CHECK” is displayed on the fluorescent display tube and the tape is rewound.
7. AMS starts in the normal direction. If the AMS count is 2 at shut down, proceed to step 8.
“NG” is displayed at other times, and the deck stops.
8. AMS starts in the opposite direction. If the AMS count is 2 at shut down again, “OK” is displayed.
“NG” is displayed at other times.
Aging Mode
During the aging mode, both the CD player and tape deck are executed together.
• If an error occurs:
Aging stops, and the error state is displayed on the fluorescent display tube.
• If no error occurs:
Aging is repeated.
Procedure:
1. Press the 1/ubutton to turn the set ON.
2. Load 10 minute tapes with unbent rec-proof tabs in decks A and B.
3. Set CDs on the DISC 1 and DISC 4 tables.
4. Set the CD mode REPEAT to OFF and PLAY MODE to ALL DISCS.
(Press the PLAY MODE and REPEAT buttons to set these modes.)
5. Press the FUNCTION button to switch the function to “CD”.
6. Press the three buttons t/CLOCK SET , ENTER , and DISC 4 button simultaneously.
7. Aging starts.
8. To end aging, press the 1/ubutton to turn the set OFF.
Aging Sequence:
Aging is performed in the following sequence.
• Tape Deck
1. The tape in deck A is rewound. “TAPE A AG-1” is displayed.
2. The FWD side of deck A is played for two minutes.
“TAPE A AG-2” is displayed.
3. The tape in deck A is fast forwarded. “TAPE A AG-3” is displayed. Fast forward is carried out for 20 seconds or to the tape end.
4. The RVS side of deck A is played for two minutes.
“TAPE A AG-4” is displayed.
5. The tape in deck A is rewound. “TAPE A AG-5” is displayed.
6. The FWD side of deck B is played for two minutes.
“TAPE B AG-2” is displayed.
7. The tape in deck B is fast forwarded. “TAPE B AG-3” is displayed. Fast forward is carried out for 20 seconds or to the tape end.
8. The RVS side of deck B is played for two minutes.
“TAPE B AG-4” is displayed.
9. The tape in deck A is rewound. “TAPE A AG-5” is displayed.
10. Repeated from step 2.

13
SELF-DIAGNOSIS
This model has the self-diagnosis function for the VIDEO and AUDIO decoder sections.
Immediately after the power on, the self-diagnosis function searches each operation of IC’s around the mechanism control microcomputer
(IC701).
The results can be checked by D502 of the VIDEO board.
• When D502 turns on the IC is normal.
• When D502 flashes twice, the MPEG decoder (IC505) is abnormal.
• When D502 flashes three times, the MPEG decoder (IC505) or
the DRAM (IC507) is abnormal.
[VIDEO BOARD] (SIDE A)
D502
IC505
100 91
33 64
90
65
1
32

14
[VIDEO CD COLOR-BARS MODE]
On this mode, the data of the color-bars signal as a picture signal and the 1kHz sine wave signal as a sound signal are output by the
mechanism control microcomputer (IC502) for video CD signal check. When measurement of the voltage and waveform on the VIDEO
board, perform it in this mode.
For refernce, the color-bars signal can be observed at J302 (VIDEO OUT) and the sound signal can be observed at J101 (VIDEO/MD
(AUDIO) OUT) using an oscilloscope.
1. Connect the lead wire to both ends of the land of SL503 of the VIDEO board.
2. Turn the power on. Press FUNCTION button to select CD.
3. After 2 or 3 seconds later, connect the lead wire.
4. After measuring, remove the lead wire connected.
[VIDEO BOARD] (SIDE A)
[VIDEO BOARD] (SIDE B)
SL501
D502
SL502
IC507
IC505
CT503
SL503
TEST MODE
VIDEO
FREQUENCY
SL501
IC502
SL502
SL503
TEST
MODE

15
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
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 1 dB of peak.
test tape
P-4-A100
(10kHz, –10dB) MD OUT level meter
set +
–
L-CH
peak
R-CH
peak
screw
position
output
level within
1 dB
L-CH
peak R-CH peak
screw
position
within 1dB
Mode
FWD
FWD
back tension
REV
REV
back tension
FF/REW
FWD tension
REV tension
Torque meter
CQ-102C
CQ-102C
CQ-102RC
CQ-102RC
CQ-201B
CQ-403A
CQ-403R
Meter reading
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
(0.02 – 0.08 oz • inch)
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
(0.02 – 0.08 oz • inch)
71 to 143 g • cm
(0.98 – 1.99 oz • inch)
100 g or more
(3.53 oz or more)
100 g or more
(3.53 oz or more)
SECTION 5
ELECTRICAL ADJUSTMENTS
SECTION 4
MECHANICAL ADJUSTMENTS
DECK SECTION 0 dB=0.775V
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. Switchesand controls should be set as follows unless otherwise
specified.
Record/Playback Head Azimuth Adjustment
(Deck A, Deck B)
Note: Perform this adjustments for both decks.
Procedure:
1. Mode : Playback
Tape Signal Used for
P-4-A100
WS-48B
P-4-L300
10 kHz, –10 dB
3 kHz, 0 dB
315 Hz, 0 dB
Azimuth Adjustment
Tape Speed Adjustment
Level Adjustment

16
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
Adjustment Location: Playback Head (DeckA)
Record/Playback/Erase Head (Deck B)
3. Mode: Playback Tape Speed Adjustment (Deck A)
Note: Set the test mode using the following method and begin tape
speed adjustment.
In the test mode, the speed will switch to double speed or
normal speed each time the HI-SPEED DUB button is pressed.
Procedure:
With the power turned ON, press the t/CLOCK SET button,
ENTER button, and DISC 3 button simultaneously.
(The “VOLUME” on the fluorescent display tube will blink while
in the test mode.)
To exit the test mode, press the 1/u button.
1. Insert the WS-48B into deck B.
2. Press the ·button of deck B.
3. Pressthe HI-SPEEDDUB buttonandplaythetape atdoublespeed.
4. Adjust RV1001 of the LEAF SW board so that the reading of
the frequency counter becomes 6000 ± 180 Hz.
5. Pressthe HI-SPEEDDUB buttonandplaythetapeatnormalspeed.
6. Adjust RV1002 of the LEAF SW board so that the reading of
the frequency counter becomes 3000 ± 90 Hz.
Adjustment Location: LEAF SW board
SampleValue ofWow and flutter
W.RMS (JIS) less than 0.3%
(test tape: 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 the following adjustment level.
Adjustment level:
CN301 playback 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
Adjustment Location
[LEAF SW BOARD] (Conductor Side)
test tape
P-4-A100
(10kHz, –10dB) oscilloscope
set
Waveform of oscilloscope
in phase 45
°
90 °
135 °
180 °
good wrong
MD OUT
Reverse Foward
Remove the cassette lid.
test tape
P-4-L300
(315Hz, 0dB) level meter
set
MD OUT
RV1002
RV1001
RV1002(Normal Speed)
RV1001(High Speed)

17
Record Bias Adjustment (Deck B)
Procedure:
INTRODUCTION
Whenset tothe testmode performedinTape 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 1.
(After recording, press the 0button without stopping will return
to the position where recording was started.)
1. Press FUNCTION button to selectVIDEO 1. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B, press the rREC button, and then
press the ·button to start recording.
3. Mode: Record
4. Mode: Playback
adjustment level as follows.
If these levels do not adjustment level, adjust the RV341 (L-
CH) and RV441 (R-CH) on theAUDIO board to repeat steps 3
and 4.
Adjustment level: The playback output of 10 kHz level difference
against 315 Hz reference should be ± 1.0 dB.
Adjustment Location: AUDIO board
Record Level Adjustment (Deck B)
Procedure:
INTRODUCTION
Whenset tothe testmode performedinTape 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 1.
(After recording, press the 0button without stopping will return
to the position where recording was started.)
1. Press FUNCTION button to selectVIDEO 1. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B, press the rREC button, and then
press the ·button to start recording.
3. Mode: Record
4. Mode: Playback
5. Confirm playback the signal recorded in step 2 become
adjustment level as follows.
If these levels do not adjustment level, adjust the RV301 (L-
CH) and RV351 (R-CH) on the MAIN board to repeat steps 3
and 4.
Adjustment level:
CN403 playback level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location: MAIN board
Adjustment Location:
[AUDIO BOARD] (Conductor Side)
5. Confirm playback the signal recorded in step 2 become
[MAIN BOARD] (Conductor Side)
recorded
position level meter
set
MD OUT
AF OSC
VIDEO 1 (AUDIO) IN
1) 315 Hz
2) 10 kHz
blank tape
CS-123
set
attenuator 600
Ω
} 50 mV (–23.8 dB)
AF OSC
VIDEO 1 (AUDIO) IN
315Hz 50 mV (–23.8 dB)
blank tape
CS-123
set
attenuator 600
Ω
recorded
position level meter
set
MD OUT
Record Level (Lch)
RV301
RV351
Record Level (Rch)
IC3015643 42
29
28
15
14
1
1
3
RV441 RV341
RV301(Lch),RV401(Rch)
Playback Level (Deck B)
RV301 RV401
RV341(Lch),RV441(Rch)
Record Bias RV311(Lch),RV411(Rch)
Playback Level (Deck A)
RV311 RV411

18
CD SECTION
Note:
1. CD Block is basically constructed to operate without
adjustment. Therefore, check each item in order given.
2. UseYEDS-18 disc (3-702-101-01) 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
Adjustment Location: BD board
Procedure :
1. Connect the oscilloscope to test points TP (FE) and TP (VC).
2. Connect TP (FEI) and GND, and TP (AGCCON) and GND of
the BD board with lead wires.
3. Press the 1/ubutton to turn the set ON.
4. With the disc (YEDS-18) loaded, press the ^button and
perform focus search. (Focus search will be performed in the
same way even while the disc table is pushed in and out.)
5. Check the symmetry and peak to peak level of the oscilloscope
waveform (S curve) at this time.
S-curve waveform
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.
Adjustment Location: BD board
RF Level Check
Procedure :
1. Connect oscilloscope to test point TP (RF) and TP (VC) on
BD board.
2. Connect TP (AGCCON) and GND of the BD board with lead
wires.
3. Press the 1/ubutton to turn the set ON.
4. Put disc (YEDS-18) in and playback 5track.
5. Confirm that oscilloscope waveform is clear and check RF
signal level is correct or not.
6. After check, remove the lead wire connected in step 2.
oscilloscope
BD board
TP (FE)
TP (VC) +
–
oscilloscope
BD board
TP (RF)
TP (VC) +
–
E-F Balance (Traverse) Check
oscilloscope
BD board
TP (TE)
TP (VC) +
–
Adjustment Location: BD board
Procedure :
1. Connect oscilloscpe to test point TP (TE) on BD board.
2. Short-circuit SL502 of the video board to GND.
3. Turned Power switch on. Press FUNCTION button to select
CD.
4. Put disc (YEDS-18) in to play the number five track.
5. Press the PLAY MODE button. (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 ± 22%
Traverse waveform
0V
level : 1.3 ± 0.6 Vp-p
A (DC voltage)
Center of the waveform
B
7. Press the PLAY MODE button. (The tracking servo and
sledding servo are turned ON.) Confirm the C (DC voltage) is
almost equal to the A (DC voltage) is step 7.
Traverse waveform
0V C (DC
voltage)
Tracking servo
Sled servo
OFF
Tracking servo
Sled servo
ON
symmetry
A
B
Within 4.0
± 1.0 Vp-p
Note: Clear RF signal waveform means that the shape “◊” can be
clearly distinguished at the center of the waveform.
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.75 ± 0.25 Vp-p
8. Desolder the short-land (SL502) short-circuited at step 2.
Adjustment Location: BD board

1919
6-1. CIRCUIT BOARDS LOCATION
SECTION 6
DIAGRAMS
VIDEO SECTION
Frequency adjustment
1. Connect the frequency counter to check point TP508 (27MHz)
of the VIDEO board.
2. Adjust CT503of theVIDEO boardso thatthefrequencycounter
read 27MHz ± 80Hz at STOP condition.
[ VIDEO BOARD ] – SIDE B –
Adjustment Location :
[ VIDEO BOARD ] – SIDE A –
frequency counter
VIDEO board
(27 MHz) +
–
SL501
D502 SL502
CT503
TP508
SL503
TEST MODE
VIDEO
FREQUENCY
(27MHz)
(GND)
IC507
IC505
Adjustment Location :
[ BD BOARD ] — SIDE B —
TP
(VC)
TP
(RF)
TP
(TE)
TP
(IOP)
TP
(FE)
TP
(AGCCON)
TUNER UNIT
SURROUND AMP board
JACK board
VIDEO boar
d
TC-B board
TC-A board
FL board
PANEL VR board
FRONT INPUT board
TRANS board
MAIN boar
d
PA board
CD-L board
CD-R board
LED (PANEL) board
DOOR SW board
BD board
LED (CD) board
CD MOTOR board
TABLE SENSOR board
AUDIO board
LEAF SW board
SL501 IC502
IC506
(27MHz)
(GND)
SL502
SL503
TEST
MODE
TP508

HCD-VR90AV
2020
6-2. BLOCK DIAGRAMS
BD SECTION
E
F
A
B
C
D
DRIVE
Q101
LD
RF EQ
AMP
RF
SUMMING
AMP
FOCUS
ERROR
AMP
TRACKING
ERROR
AMP
APC LD
AMP
VC
BUFFER
VC
REF
RF AMP
IC103
DIGITAL SERVO
DIGITAL SIGNAL PRCESSOR
IC101 IC781
LASER
DIODE
DETECTOR
OPTICAL PICK-UP BLOCK
(KSS-213D/Q-NP)
A
C
D
B
E
F
LD
POWER
PD
LD
PD
LD
A
C
D
B
E
FTE
FE
RFO
RFI
ASYMMETRY
CORRECTION
SERVO
AUTO
SEQUENCER
INTEG-
RATOR DIGITAL
PLL
EFM
DEMODULATOR REGISTER
SUB CODE
PROCESSOR
ERROR
CORRECTOR
DATA BUS
32K
RAM
D/A
INTERFACE
CD DIGITAL
OUT
OPTICAL
DIGITAL
OUT DOUT
SERVO
INTERFACE
DIGITAL
CLV
LD ON
OP AMP
ANALOG SW A/D CONVERTER
TRACKING
PWM
GENERATOR
FOCUS
PWM
GENERATOR
SLED
PWM
GENERATOR
PWM
GENERATOR
VC
TRACKING
SERVO
FOCUS
SERVO
SLED
SERVO
SERVO DSP
TFDR
TRDR
FFDR
FRDR
SFDR
SRDR
MDP
DETECTOR
MIRR
DFCT
FOK
D OUT
PCM-D
S STOP
RFDC
FE
TE
CE
VC SE
CPU
INTERFACE
SENS
DATA
XLAT
CLOK
CLOCK
GENERATOR XTAI
XTSL
M
M
TRACKING
COIL
FOCUS
COIL
M102
SLED
MOTOR
M101
SPINDLE
MOTOR
T+
T–
F+
F–
SD+
SD–
SP+
SP–
FOCUS/TRACKING COIL DRIVE
SPINDLE/SLED MOTOR DRIVE
IC102
VC
TFDR
TRDR
FFDR
FRDR
SFDR
SRDR
XRST
MUTE
16
S101
LIMIT SW
SQCK
A+5V
IC104
XRST
ADATA
BCLK
LRCK
MCK
SENS
CTRL1
DATA
SCLK SCLK
XLT
CLK
SCOR
SQSO SCOR
SUBQ
SQCK
CTRL2
XRST
LD ON
LRCK
BCLK
C2PO
MUTE
MUTE
C2PO
RF AC
ASYI
ASYO
CONTROL
SIGNAL
BLOCK
SERVO
BLOCK
VCC
VC
: CD VIDEO
VIDEO
SECTION
(Page 21)
A
(XTAL 33.8MHz)
42
5
7
8
6
11
10
3
4
23
24
27
25
20
22
21
12
13
17
14
16 50
48
49
43
38
41
39
40
42
32
31
34
33
30
29
25
64
67
66
14
65
71
3
7
69
15
6
5
4
77
76
8
26
82
1
12
11
14
13
17
18
15
16
3
2
6
5
INTEG-
RATOR
• SIGNAL PATH
: CD AUDIO
: Digital out
LPH