Sony HCD-VX880AV User manual

1
HCD-VX880AV
Chinese Model
SPECIFICATIONS
MINI Hi-Fi COMPONENT SYSTEM
— Continued on next page —
Model Name Using Similar Mechanism NEW
Mechanism Type CDM38LH-26BD36L
Base Unit Type BU-26BD36L
Optical Pick-up Type KSS-213D/Q-NP
Model Name Using Similar Mechanism HTC-5550
Tape Transport MechanismType TCM-230AWR2
CD
SECTION
MICROFILM
SERVICE MANUAL
HCD-VX880AV is the Amplifier,
Video CD player, Tape Deck and
Tuner section in MHC-VX880AV.
TAPE DECK
SECTION

2
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 PUBLISHED BY SONY.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation 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.
Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.
This appliance is classified as
a CLASS 1 LASER product.
The CLASS 1 LASER PROD-
UCT MARKING is located on
the rear exterior.

3
7. EXPLODEDVIEWS
7-1. Case Section........................................................................ 63
7-2. Chassis Section ................................................................... 64
7-3. Front Panel Section ............................................................. 65
7-4. CD Mechanism Deck Section-1 (CDM38LH-26BD36L) .. 66
7-5. CD Mechanism Deck Section-2 (CDM38LH-26BD36L) .. 67
7-6. Base Unit Section (BU-26BD36L) ..................................... 68
7-7. TC Mechanism Section-1 (TCM230AWR2) ...................... 69
7-8. TC Mechanism Section-2 (TCM230AWR2) ...................... 70
8. ELECTRICAL PARTS LIST ....................................71
TABLE OF CONTENTS
1. SERVICING NOTES ...................................................4
2. GENERAL ..................................................................10
3. DISASSEMBLY
3-1. Loading Panel ..................................................................... 12
3-2. Front Panel .......................................................................... 12
3-3. Cassette Lid and Tape Mechanism...................................... 13
3-4. CD SW Board and Panel Board .......................................... 13
3-5. Disc Tray ............................................................................. 14
4. MECHANICAL ADJUSTMENTS............................15
5. ELECTRICAL ADJUSTMENTS .............................15
6. DIAGRAMS
6-1. Circuit Boards Location...................................................... 20
6-2. Block Diagrams
• CD Section ....................................................................... 21
• Video Section ................................................................... 22
• Deck Section .................................................................... 23
• Main 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. Schematic Diagram – Deck Section – ................................ 30
6-6. Printed Wiring Board – Deck Section –.............................. 31
6-7. Printed Wiring Board – Video Section – ............................. 32
6-8. Schematic Diagram – Video (1/2) Section – ....................... 33
6-9. Schematic Diagram – Video (2/2) Section – ....................... 34
6-10. Schematic Diagram – Main (1/4) Section – ....................35
6-11. Schematic Diagram – Main (2/4) Section – ....................36
6-12. Schematic Diagram – Main (3/4) Section – ....................37
6-13. Schematic Diagram – Main (4/4) Section – ....................38
6-14. Printed Wiring Board – Main Section –........................... 39
6-15. Printed Wiring Board – Panel Section – .......................... 40
6-16. Schematic Diagram – Panel (1/2) Section – .................... 41
6-17. Schematic Diagram – Panel (2/2) Section – .................... 42
6-18. Printed Wiring Board – Leaf SW Section –..................... 43
6-19. Schematic Diagram – Leaf SW Section – ....................... 43
6-20. Schematic Diagram – Surround Section – ....................... 44
6-21. Printed Wiring Board – Surround Section – .................... 44
6-22. Schematic Diagram – Power Section –............................ 44
6-23. Printed Wiring Board – Power Section – ......................... 44
6-24. Schematic Diagram – Trans Section – ............................. 45
6-25. Printed Wiring Board – Trans Section – .......................... 45
6-26. Schematic Diagram – Front Amp Section – .................... 46
6-27. Printed Wiring Board – Front Amp Section –.................. 47
6-28. Schematic Diagram – CD Motor Section – ..................... 48
6-29. Printed Wiring Board – CD Motor Section – .................. 49
6-30. IC Block Diagrams .......................................................... 50
6-31. IC Pin Functions .............................................................. 52

4
SECTION 1
SERVICING NOTES
CD-TEXT
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.
HOW TO OPEN THE DISC TRAY WHEN POWER SWITCH
TURNS OFF
Note for Installation (ROTARY ENCODER)
1 Remove the Case.
3 Pull-out the disc tray.
2 Turn the cam to the direction
of arrow.
BU cam
Groove Section A
Note:When attaching the Base unit, Insert the
section A into the groove of BU cam.
Note:When attaching the BU cam,
engage the Rotary encoder
switch as shown in the figure.

5
SELF-DIAGNOSIS
This unit is equipped with a self-diagnosis function.
The function is used for diagnosing the conditions of the circuits of
the VIDEO board.
The circuits can be determined if normal or abnormal by the light-
ing of D502 of the VIDEO board.
Lighting of D502
When lit : Operates normally
Blinks repeatedly : The circuit may be faulty.
[VIDEO BOARD] (SIDE B)
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, ob-
serve from more than 30 cm away from the objective lens.
CN501
130
80 SL501
SL502
SL50
3
CN502
51
IC505
31
50
100
81
D502

6
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 p, ENTER/NEXT , and 1/usimultaneously.
2. “COLD RESET” is displayed on the fluorescent display tube and reset is executed.
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 1/ubutton to turn the set ON.
2. Press CD LOOP button and 1/ubutton simultaneously.
3. 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 p, ENTER/NEXT , 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 optical pick-up.
Procedure:
1. Press 1/ubutton to turn the set ON.
2. Press three buttons p, ENTER/NEXT , and §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 the )+ button is pressed, the optical pick-up moves outside. When – 0button is pressed, it
moves inside.
5. To exit from this mode, perform as follows:
1) Move the optical pick-up to the most inside track.
2) Execute MC cold reset. (Press the three buttons p, ENTER/NEXT , and 1/ubutton simultaneously.)
Note:
• 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.
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/NEXT 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 p, ENTER/NEXT , 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 “K 0 V0 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 0AMS )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.

7
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 unit ON.
2. Set the tape (AMS-110A).
3. Press the three buttons p, ENTER/NEXT , and DISC 3 button simultaneously.
4. “TEST MODE” is displayed on the fluorescent display tube.
5. Press the FUNCTION button and switch the function to the deck with the tape (AMS-110A).
6. Press the CD SYNC 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.
Note: The pbutton of CD section will become effective and the aging of CD section will stop sometime, if the buttons described in step 3
are not pressed simultaneously. In that case, press ^button and operate the CD section.
SELF-DIAGNOSIS
This model has the self-diagnosis function for the VIDEO andAUDIO 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.
Oscilloscope (Waveform) Symptom
No error
MPEG decoder (IC506)
error
MPEG decoder (IC506)
or
DRAM (IC507) error
[VIDEO BOARD] (SIDE B)
H
L
Li
g
ht
2 time blinkin
g
H
L
H
L
3 time blinkin
g
CN501
130
80
D502
SL501
SL502
SL50
3
CN502
51
IC505
31
(GND)
CT503
VIDEO
Frequency
Adjustment
Check point
(27 MHz)50
100
81

8
Aging Mode
This mode can be used for operation check of tape deck section.
• If an error occurred:
The aging operation stops and display then status.
• If no error occurs:
The aging operation continues repeatedly.
Procedure:
1. Load the tapes into the decks A and B respectively.
2. Press the FUNCTION button to select the function “CD”.
3. Press the PLAY MODE button to set the “ALL DISCS” mode,
and press the REPEAT button to “REPEAT” off.
4. Press three buttons of p, ENTER/NEXT , and DISC SKIP/
EX-CHANGE simultaneously.
5. The aging mode is activated, if the indicator of disc tray number
on the fluorescent indicator tube is blinking.
6. 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”)
• The sequence during the aging mode is following as below.
• If an error occurred, stop display that step.
Aging mode sequence:
Rewind the tape A and B
“TAPE A AG-1”
Shut off
2 mimutes
Shut off or 20 seconds
2 minutes
2 minutes
Shut off or 20 seconds
Shut off
2 minutes
Shut off
FWD piay the tape A
“TAPE A AG-2”
Fast forward the tape A
“TAPE A AG-3”
REV play the tape A
“TAPE A AG-4”
Rewind the tape A
“TAPE A AG-5”
FWD play the tape B
“TAPE B AG-2”
Fast forward the tape B
“TAPE B AG-3”
REV play the tape B
“TAPE B AG-4”
Rewind the tape B
“TAPE B AG-5”
Note: “TAPE * AG_*” is display of each step.

9
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 (IC505) for video CD signal check. When measurement of the voltage and waveform on the VIDEO
board, perform it in this mode.
For reference, the color-bars signal can be observed at J502 (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 B)
CN501
1
30
80
SL501
SL502
SL503
CN502
51
IC505
3150
100
81

10
LOCATION OF PARTS AND CONTROLS
11/u button and indicator
2DEMO (STANDBY) button
3DISC 1 button and indicator
4DISC 2 button and indicator
5DISC 3 button and indicator
6DISC SKIP/EX–CHANGE button
7§(Eject) button
8SYNC BASS H indicator
9SVIDEO/VCD indicator
10 PBC indicator
11 PBC OFF indicator
12 SYNC BASS L indicator
13 TUNER/BAND button
14 ^(CD) button and indicator
15 pbutton
16 SYNC BASS button
17 SYNC EQ button
18 KARAOKE PON/MPX button
19 CD NON-STOP button and indicator
20 REC PAUSE/START button and
indicator
21 DSP button and indicator
22 DBFB button
23 HI-DUB button
24 CD SYNC button
25 PHONES jack
26 VOLUME knob
27 ENTER/NEXT button and indicator
28 )+ button and indicator
29 PRO LOGIC button and indicator
30 JOG/0x)dial and indicator
31 GROOVE button and indicator
32 0– button and indicator
33 DVD 5.1 CH button
34 CD FLASH button
35 CD LOOP button
36 MIC 2 jack
37 TIMER SELECT button and indicator
38 CLOCK/TIME SET button
39 MIC 1 jack
40 SPECTRUMANALYZER button
41 DISPLAY button
42 MIC LEVEL knob
43 REPEAT/STEREO/MONO button
44 PLAY MODE/DOLBY NR button
45 EDIT DIRECTION TUNER MEMORY
button
46 ECHO LEVEL knob
47 P FILE MEMORY button
48 GEQ CONTROL button
49 FILE SELECT button
50 EFFECT button
51 NEXT button
52 PREV button
53 RETURN button
54 SELECT button
55 ((TAPE B) button and indicator
56 9(TAPE B) button and indicator
57 ((TAPE A) button and indicator
58 9(TAPE A) button and indicator
59 FUNCTION button
60 SYNC EQ indicator
61 Remote sensor
62 EFFECT indicator
63 Display Window
64 Disc tray
SECTION 2
GENERAL
Front Panel
321
64
63
62 8
12
9
10
11
61
33 32 31
46
60
56575859
4567
55
51525354
47484950 15 14 13
20
23
24
25
26
27
28
29
30
1819 17 16
22 21
39
42
4041
44 4345
3435
36
3738

11
This section is extracted from
instruction manual.

12
SECTION 3
DISASSEMBLY
Note: Follow the disassembly procedure in the numerical order given.
3-1. LOADING PANEL
3-2. FRONT PANEL
3 Loading panel
assembly
2 Pull-out the disc tray.
1 Turn the cam to the direction
of arrow.
Claws
3 Screw
(
BVTT 3x8
)
4 Screw (BVTT 3x8)
0 Front panel
!¢ Screw (BVTP 3x8)
!∞ Video board
6 Screw (BVTP 3x10)
!£ Two screws (BVTP 3x8)
5 Screw
(BVTP3x10)
1 Screw (BVTT 3x6)
2 Screw (BVTT 3x6)
7 Flat type wire
(CN141)
8 Flat type wire
(CN131)
Lead wire
Lead wire
9 Flat type wire
(CN132)
!¡ Flat type wire
(CN501)
!™ Flat type wire
(CN502)

13
3-3. CASSETTE LID AND TAPE MECHANISM
3-4. CD SW BOARD AND PANEL BOARD
1 Release
3 Cassette holder (R)
assembly
4 Cassette holder (L)
assembly
Portion A
Portion A
5 Tension spring
7 Two screws
(BVTP2.6x8)
8 Three screws
(BVTP2.6x8)
9 Tape mechanism
6 Tension spring
2 Release
Portion B
Portion B
Note for installation
4 Knob (Jog)
5 Knob (Vol)
9 Three screws
(BVTP2.6x8)
3 CD SW board
0 Six screws
(BVTP2.6x8)
!¡ Four screws
(BVTP2.6x8)
!™ Panel board
2 Three screws
(BVTP2.6x8)
8 Flat type wire
(CN601)
1 Three screws
(BVTP2.6x8)
7 Nut
6 Nut

14
3-5. DISCTRAY
(Perform after removing the front panel.) Note:When installing the Disc tray, pull around the flat type wire to
pass through the claw
A and claw B , as shown in the figure.
Claw
B
Claw A
1
Turn the cam the
direction of arrow.
2 Pull-out the disc tray.
5 Remove the disc tray.
4 Two claws
3 Flat type wire (8 core)

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 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
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)
Record/Playback Head Azimuth Adjustment
(Deck A, Deck B)
Note: Perform this adjustments for both decks.
Procedure:
1. Mode : Playback
Signal Used forTape
SECTION 4
MECHANICAL ADJUSTMENTS
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
SECTION 5
ELECTRICAL ADJUSTMENTS
DECK SECTION 0 dB=0.775V
1. Demagnetize the record/playback head with a head damagnetizer.
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 sup-
ply 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 adjust-
ment.)
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.
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
LevelAdjustment
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
(J101) 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

16
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
Adjustment Location: Playback Head (Deck A)
Record/Playback/Erase Head (Deck B)
3. Mode: Playback Tape Speed Adjustment (Deck B)
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 DUB button is pressed.
Procedure:
With the power turned ON, press the pbutton, ENTER/NEXT
button, and DISC 3 button simultaneously.
(The “CD TYPE INDICATOR” 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. Press the HI DUB button and play the tape at double speed.
4. Adjust RV1001 of the LEAF SW board so that the reading of
the frequency counter becomes 6000 ± 180 Hz.
5. Press the HI DUB button and play the tape at normal speed.
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 of Wow 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:
J101 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]
test tape
P-4-A100
(10kHz, –10dB) oscilloscope
set
Waveform of oscilloscope
in phase 45
°
90 °
135 °
180 °
good wrong
MD OUT
(J101)
test tape
P-4-L300
(315Hz, 0dB) level meter
set
MD OUT
(J101)
RV1002 RV1001
RV1002(Normal Speed
)
RV1001(High Speed)
Reverse Foward

17
Record Bias Adjustment (Deck B)
Procedure:
INTRODUCTION
When set to the test mode performed in Tape Speed Adjust-
ment,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 ad-
justment. During recording, the input signal FUNCTION will auto-
matically switch to VIDEO.
(After recording, press the – 0button without stopping will
return to the position where recording was started.)
1. Press FUNCTION 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, press the rREC button, and then
press the ^button to start recording.
3. Mode: Record
5. Confirm playback the signal recorded in step 2 become adjust-
ment 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
When set to the test mode performed in Tape Speed Adjust-
ment, 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 au-
tomatically switch to VIDEO.
(After recording, press the – 0button without stopping will
return to the position where recording was started.)
1. Press FUNCTION button to select VIDEO 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 adjust-
ment 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:
J301 playback level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location: MAIN board
Adjustment Location:
[AUDIO BOARD] (Conductor Side)
4. Mode: Playback
[MAIN BOARD] (Conductor Side)
recorded
position level meter
set
MD OUT
(J101)
AF OSC
VIDEO (AUDIO) IN (J101)
1) 315 Hz
2) 10 kHz
blank tape
CS-123
set
attenuator 600
Ω
} 50 mV (–23.8 dB)
AF OSC
VIDEO (AUDIO) IN (J101)
315Hz 50 mV (–23.8 dB)
blank tape
CS-123
set
attenuator 600
Ω
recorded
position level meter
set
MD OUT
(J101)
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
IC301
Record Level (L CH)
RV301
CN303 RV351
Record Level (R CH)
56
43 42 29
28
15
14
1

18
CD SECTION
Note:
1. CD Block is basically constructed to operate without adjustment.
Therefore, 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 10MΩimpedance.
4. Clean the object lensby anapplicator withneutral detergentwhen
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 (FE1) and TP (VC), 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 aspossible and lightup the bright-
ness 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 sig-
nal 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) and TP (VC) 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/DOLBY NR button. (The tracking
servo and the sledding servo are turned OFF.)
6. Check the level B of the oscilliscope's waveform and theA(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/DOLBY NR 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 : 1.45 ± 0.3 Vp-p
8. Desolder the short-land (SL502) short-circuited at step 2.
Adjustment Location: BD board

19
VIDEO SECTION
Frequency adjustment
1. Connect the frequency counter to check point (27MHz) of the
VIDEO board.
2. Adjust CT503 of the VIDEO board so that the frequency counter
read 27MHz ± 80Hz at STOP condition.
Adjustment Location :
[VIDEO BOARD] (SIDE B)
frequency counter
VIDEO board
(27 MHz) +
–
Adjustment Location :
[BD BOARD] (SIDE B)
TP (VC)
TP (RF)
TP (TE)
TP (FE)
IC102
IC103
IC101
TP (FE)
TP
(AGCCON)
CN501
130
80 SL501
SL502
SL50
3
CN502
51
IC505
31
(GND)
CT503
VIDEO
Frequency
Adjustment
Check point
(27 MHz)50
100
81
D502

20
SECTION 6
DIAGRAMS
6-1. CIRCUIT BOARDS LOCATION
MAIN board
PANEL board
CD SW board
TUNER unit
TRANS board
VIDEO board
5V power board
SENSOR board
CONNECTOR board
BD board
MOTOR (SLIDE) board
MOTOR (TURN) board
3CH AMP board
FRONT AMP board
AUDIO board
LEAF SW board
TUNERunit is supplied as
the assembled block.