Sony HCD-LX7 User manual

1
HCD-LX7/LX8
AEP Model
UK Model
HCD-LX7
E Model
Australian Model
HCD-LX8
SPECIFICATIONS
Photo: HCD-LX8
COMPACT HiFi STEREO SYSTEM
— Continued on next page —
Model Name Using Similar Mechanism HCD-DR4/XB500
CD Mechanism Type CDM37M-5BD32L
Base Unit Type BU-5BD32L
Optical Pick-up Type KSS-213D/Q-NP
Model Name Using Similar Mechanism HCD-GRX10AV/RX110AV
Tape Transport Mechanism Type TCM-230PWR1
CD
SECTION
TAPE DECK
SECTION
SERVICE MANUAL
HCD-LX7/LX8 is the tuner, deck, CD and
amplifier section in LBT-LX7/LX8.

2
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.
SAFETY-RELATED COMPONENT WARNING !!
COMPONENTSIDENTIFIEDBYMARK 0OR DOTTEDLINE
WITH MARK 0ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS
WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS
MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.
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.
This caution
label is located
inside the unit.

3
MODEL PARTS No.
LX7: AEP, UK, CIS model 4-225-529-1 s
LX8: E, AR model 4-225-529-2 s
LX8: SP, MY model 4-225-529-3 s
LX8: MX model 4-225-529-4 s
LX8: AUS model 4-225-529-5 s
LX8: EA model 4-225-529-6 s
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.
LASER DIODE AND FOCUS SEARCH OPERATION
CHECK
Carry out the “S curve check” in “CD section adjustment” and check
that the S curve waveform is output four times.
MODEL IDENTIFICATION
— BACK PANEL —
• Abbreviation
SP : Singapore model
MX : Mexican model
AUS : Australian model
EA : Saudi Arabia model
AR : Argentine model
MY : Malaysia model
Parts No.

4
7. EXPLODEDVIEWS
7-1. Case and Back Panel Section .............................................. 53
7-2. Front Panel Section 1 .......................................................... 54
7-3. Front Panel Section 2 .......................................................... 55
7-4. Chassis Section ................................................................... 56
7-5. TC Mechanism Section 1 (TCM230PWR1)....................... 57
7-6. TC Mechanism Section 2 (TCM230PWR1)....................... 58
7-7. CD Mechanism Section (CDM37M-5BD32L)................... 59
7-8. Base Unit Section (BU-5BD32L) ....................................... 60
8. ELECTRICAL PARTS LIST ........................................ 61
1. SERVICING NOTE .......................................................... 5
2. GENERAL ....................................................................9
3. DISASSEMBLY
3-1. Front Panel .......................................................................... 11
3-2. Main Board ......................................................................... 11
3-3. Sub Panel ............................................................................ 12
3-4. CD LID Assembly .............................................................. 12
3-5. Tape Mechanism Deck and Cassette LID ........................... 12
3-6. CD Mechanism Deck .......................................................... 13
3-7. Base Unit............................................................................. 13
3-8. Disc Table ........................................................................... 13
4. MECHANICAL ADJUSTMENTS ..........................14
5. ELECTRICAL ADJUSTMENTS ............................... 14
6. DIAGRAMS
6-1. Circuit Boards Location ...................................................... 17
6-2. Block Diagrams
• BD (CD) Section.............................................................. 18
• Deck Section .................................................................... 19
• Main (1/2) Section ........................................................... 20
• Main (2/2) Section ........................................................... 21
• Power Section (LX8 model) ............................................ 22
• Power Section (LX7 model) ............................................ 23
• Display Section ................................................................ 24
6-3. Printed Wiring Board – BD (CD) Section – ....................... 26
6-4. Schematic Diagram – BD (CD) Section – .......................... 27
6-5. Printed Wiring Board – Main Section – .............................. 28
6-6. Schematic Diagram – Main (1/3) Section – ........................ 29
6-7. Schematic Diagram – Main (2/3) Section – ........................ 30
6-8. Schematic Diagram – Main (3/3) Section – ........................ 31
6-9. Schematic Diagram – Deck Section –................................. 32
6-10. Printed Wiring Board – Deck Section – ........................... 33
6-11. Schematic Diagram – Power Section – ............................ 34
6-12. Printed Wiring Board – Power Section – ......................... 35
6-13. Schematic Diagram – Panel FL Section – ........................ 36
6-14. Printed Wiring Board – Panel FL Section – ..................... 37
6-15. Schematic Diagram – Panel VR Section – ....................... 38
6-16. Printed Wiring Board – Panel VR Section – .................... 39
6-17. Schematic Diagram – TC Panel Section – ....................... 40
6-18. Printed Wiring Board – TC Panel Section –..................... 41
6-19. Schematic Diagram – CD Panel Section – .......................42
6-20. Printed Wiring Board – CD Panel Section – .................... 43
6-21. Schematic Diagram – CD Motor Section – ...................... 44
6-22. Printed Wiring Board – CD Motor Section – ................... 45
6-23. Schematic Diagram – Trans Section – (LX7 model) ....... 46
6-24. Printed Wiring Board – Trans Section – (LX7 model)..... 47
6-25. Schematic Diagram – Trans Section – (LX8 model) ....... 48
6-26. Printed Wiring Board – Trans Section – (LX8 model)..... 49
6-27. Schematic Diagram – Leaf SW Section – ........................ 49
6-28. Printed Wiring Board – Leaf SW Section – ..................... 49
6-29. IC Block Diagrams ........................................................... 50
6-30. IC Pin Functions ............................................................... 50
TABLE OF CONTENTS

5
SECTION 1
SERVICING NOTE
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 c/CLOCK SET , ENTER , and "/1 simultaneously.
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 "/1button to turn the set ON.
2. Press LOOP button and "/1button 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 c/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 "/1button to turn the set ON.
2. Press three buttons c/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 the .AMS >knob is rotated in the clockwise direction, the pick-up moves outside. When
rotated counterclockwise, it 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 c/CLOCK SET , ENTER , and "/1button 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 "/1button to turn the set ON.
2. Select the function “TUNER”, and press TUNER/BAND button to select the BAND “AM”.
3. Press "/1button to turn the set OFF.
4. Press ENTER and "/1buttons 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 c/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 “K @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 .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.

6
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 "/1button to turn the set ON.
2. Set the tape (AMS-110A).
3. Press the three buttons c/CLOCK SET , ENTER , 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.
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 "/1button 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 c/CLOCK SET , ENTER , and DISC 4 button simultaneously.
7. Aging starts.
8. To end aging, press the "/1button 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 AAG-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 AAG-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 AAG-5” is displayed.
10. Repeated from step 2.

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• CD
1. The tray rotates.
2. DISC 1 is chucked.
3. The TOC is read.
4. The first track is played for 2 seconds.
5. The last track is played for 2 seconds.
6. The tray rotates.
7. DISC 4 is chucked.
8. The TOC is read.
9. The first track is played for 2 seconds.
10. The last track is played for 2 seconds.
11. Repeated from step 1.
• Display when ended abnormally
When the tape deck is abnormal:
The state when ended abnormally is displayed.
The contents of display are the same as that during aging.
When the CD player is abnormal:
A message indicating that errors such as “CD MEC ERR” have occurred.
Check the error contents in the following error history display mode.
Error History Display Mode
Mode which enables the history of error occurring in the CD player to be checked.
Execute this mode after ending the aging mode.
Procedure:
1. Press the "/1button to turn the set ON.
2. Press the three buttons c/CLOCK SET , ENTER , and CD SYNC simultaneously.
3. A message such as “EMC@@EDC**” is displayed.
@@ : Number of mechanical errors (Up to three past errors)
** : Number of errors (NO DISC ERROR) which occurs after chucking (Up to three past errors)
4. When checking the history of mechanical errors, press the PLAY MODE button. When checking errors after chucking, press the
REPEAT button to switch the display.
5. Press the "/1button to end and turn the set OFF.
6. To erase the error history, perform COLD reset.
(Press the three buttons c/CLOCK SET , ENTER , and DISC 1 simultaneously.
• Viewing the mechanical error history display
(Switch the history by pressing the PLAY MODE button.)

8
Display
E@@M#*****
@@ : Error number. 00 is the newest.
# : Operating state of table
0 : Currently in the INITIAL mode
7 : Currently rotating to the right
8 : Currently rotating to the left
A : Currently chucking down
B : Currently chucking up
* : Invalid
• Viewing the NO DISC ERROR history display
(Switch the history by pressing the REPEAT button.)
Display
E@@D##$$%*
@@ : Error number. 00 is the newest
## : Error contents
01: Focus error
02: GFS error
03: Setup error
$$ : Retries
00: NO DISC is determined without attempting chucking retry
02: NO DISC is determined after chucking retry.
% : State when determined as NO DISC
1 : When stopped
2 : At setup
3 : At TOC READ
4 : When accessing
5 : When playing
6 : When pausing
7 : When manual searching (during play)
8 : When manual searching (during pausing)
* : Invalid

9
SECTION 2
GENERAL
Front Panel
1234567 8 9101112 1413 15
16
17
18
19
20
21
24
25 26
30 31
32 33
27 28 29
36 37 38
34
35
39
40
41424344454647
48
49
50
52 53
57 58
59 60
61 62
65 66 67
54 55 56
51
63
64
68
69
70
71
72
73
74
22 23
Photo : HCD-LX8

10
This section is extracted from
instruction manual.
LOCATION OF PARTS AND CONTROLS
1"/1 (Power) button and indicator
2c/CLOCK SET button
3SLEEP button
4REC button and indicator
5DAILY button and indicator
6TUNING - button
7TUNING + button
8Display window
9ENTER/NEXT button and indicator
10 TUNER MEMORY button
11 STEREO/MONO button
12 TUNING MODE button
13 GEQ control button
14 PTY button (LX7 model only)
15 Remote sensor
16 SYNC EQ button
17 SYNC BASS button
18 SURROUND button and indicator
19 KARAOKE PON button
20 FUNCTION button
21 VOLUME knob
22 Z(A Deck) button
23 Z(B Deck) button
24 PHONES jack
25 h(B Deck) button and indicator
26 H(B Deck) button and indicator
27 x(B Deck) button
28 m(B Deck) button
29 M(B Deck) button
30 X(B Deck) button and indicator
31 zREC (B Deck) button and indicator
32 HI-SPEED DUB button
33 CD SYNC button
34 .AMS >knob
35 HX (CD) button and indicator
36 x(CD) button
37 m(CD) button
38 M(CD) button
39 DISK SKIP button
40 VIDEO2 INPUT jacks
41 REPEAT button
42 PLAY MODE button
43 DISC 1 button
44 DISC 2 button
45 DISC 3 button
46 DISC 4 button
47 DISC 5 button
48 EDIT button
49 NON-STOP button and indicator
50 FLASH button
51 LOOP button
52 DIRECTION button
53 DOLBY NR button
54 x(A Deck) button
55 m(A Deck) button
56 M(A Deck) button
57 h(A Deck) button
58 H(A Deck) button
59 MIX MIC jack
60 GUITAR jack
61 MIC LEVEL knob
62 GUITAR LEVEL knob
63 SUPER WOOFER MODE button
64 SUPER WOOFER button and indicator
65 FILE MENU button
66 GEQ CTRL button
67 ENTER button and indicator
68 GROOVE button and indicator
69 Equalizer indicators
70 EFFECT button and indicator
71 TUNER/BAND button
72 SPECTRUM ANALYZER button
73 DISPLAY button
74 DEMO (STANDBY) button
• AMS is the abbreviation for Automatic
Music Sensor.

11
4Screw(BVTP3x8)
qaScrew(BVTP3x8)
qsFour screws(BVTP3x8)
3Connector
(CN802)
6Flat type wire(CN431)
7Flat type wire(CN304)
8Flat type wire(CN303)
9Connector(CN452) 0Connector(CN702)
qdFront panel
5Two earth wirs
1Screw(BVTP3x8)
2Earth wire
SECTION 3
DISASSEMBLY
Note: Follow the disassembly procedure in the numerical order given.
3-1. FRONT PANEL
3-2. MAIN BOARD
1Two screws(BVTP3x8)
6Two screws(BVTP3x8)
qdTwo screws(BVTP3x8)
qfMain board
qsFan motor
0Back panel
7Two screws(BVTP3x8)
8Three screws(BVTP3x8)
qaTwo screws(BVTP3x8)
5Seven screws(BVTP3x8)
3Tuner
2Flat type wire(CN1)
9Connector(CN903)
4Screw(BVTP3x8)

12
3-3. SUB PANEL 3-4. CD LID ASSEMBLY
5Five screws
(BVTP2.6x8)
1Three screws
(BVTP2.6x8)
6Screw
(PTPWH3x10)
7Screw
(PTPWH3x10)
2Ornamental
plate
8Four screws
(BVTP2.6x8)
9Front input boar
d
0Sub panel block
4Connector
(CN703)
3Connector
(CN812)
Claw
1CD lid assembl
y
3Sab panel assembly
2Spring(TC lid)
3-5.TAPE MECHANISM DECK AND CASSETTE LID
1Two screws(BVTP2.6x8)
4Mechanism deck
5Two screws
(BVTP2.6x8)
2Screw(BVTP2.6x8
)
7Screw
(BVTP2.6x8)
qaSpring(deck B)
9Spring(TC- lid)
8Spring(TC- lid)
0Bracket
qdSpring(deck A)
qfHolder(deck A)
qsHolder(deck B)
3Screw(BVTP2.6x8)
6Screw(BVTP2.6x8)

13
3-6. CD MECHANISM DECK 3-7. BASE UNIT
3-8. DISCTABLE
Note:
When the disc table is installed, adjust the positions of
roller cam and mark Bas shown in the figure, then set to
the groove of disc table.
1Five screws (BVTP3x8)
2CD mechanism
deck
3Base uni
t
1Yoke fitting
2Boss
A
A
2Screw (BVTP3X8
1Screw (BVTP3X8)
4Stop screw
5Disc table
3Bracket (BU)

14
3.04 – 6.96 N • m
(31 to 71 g • cm)
(0.43 – 0.98 oz • inch)
0.20 – 0.58 N • m
(2 to 6 g • cm)
(0.02 – 0.08 oz • inch)
3.04 – 6.96 N • m
(31 to 71 g • cm)
(0.43 – 0.98 oz • inch)
0.20 – 0.58 N • m
(2 to 6 g • cm)
(0.02 – 0.08 oz • inch)
6.97 – 14.02 N • m
(71 to 143 g • cm)
(0.98 – 1.99 oz • inch)
0.98 N • m or more
(100 g or more)
(3.53 oz or more)
0.98 N • m or more
(100 g or more)
(3.53 oz or more)
CQ-102C
CQ-102C
CQ-102RC
CQ-102RC
CQ-201B
CQ-403A
CQ-403R
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
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
FWD
back tension
REV
REV
back tension
FF/REW
FWD tension
REV tension
Torque meter Meter reading
SECTION 5
ELECTRICAL 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 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
Level Adjustment
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

15
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 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 c/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 button.
1. Insert the WS-48B into deck B.
2. Press the Hbutton of deck B.
3. Press the HI-SPEED 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-SPEED 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
Sample Value 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:
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]
test tape
P-4-A100
(10kHz, –10dB)
oscilloscope
set
Waveform of oscilloscope
in phase 45°90°135°180°
good wrong
Pin 2(GND)
main board
CN301
Pin 3(L-ch)
Pin 1(R-ch)
L
R
Reverse Foward
Remove the cassette lid.
test tape
P-4-L300
(315Hz, 0dB)
level meter
set
main board
CN301
Pin 1(R-ch)
Pin 3(L-ch)
RV1002 RV1001
RV1002(Normal Speed
)
RV1001(High Speed)

16
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 1.
(After recording, press the mbutton without stopping will re-
turn 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 zREC button, and then
press the Hbutton 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 1.
(After recording, press the mbutton without stopping will re-
turn 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 zREC button, and then
press the Hbutton 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:
CN301 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
main board
CN301
Pin 1(R-ch)
Pin 3(L-ch)
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
main board
CN301
Pin 1(R-ch)
Pin 3(L-ch)
Record Level (Lch)
RV301
RV351
Record Level (Rch)
IC301 1
14 15
28
29
42
43
56
3
1
CN301
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

HCD-LX7/LX8
17
17
6-1. CIRCUIT BOARDS LOCATION
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 applicatorwithneutral detergent when
the signal level is low than specified value with the following
checks.
S Curve Check
Procedure :
1. Connect the oscilloscope to test points TP (FE) and TP (VC).
2. Connect TP (FE1) and GND, and TP (AGCCON) and GND of
the BD board with lead wires.
3. Press the "/1 button to turn the set ON.
4. With the disc (YEDS-18) loaded, press the HX 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 bright-
ness to obtain best waveform.
RF Level Check
Procedure :
1. Connect oscilloscope to test point TP (RF) and TP (VC) on BD
board.
2. Press the "/1 button to turn the set ON.
3. Put disc (YEDS-18) in and playback 5 track.
4. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
Note: Clear RF signal waveform means that the shape “◊” can be
clearly distinguished at the center of the waveform.
RF signal waveform
Adjustment Location :
[ BD BOARD ] — SIDE A —
Procedure:
1. Connect oscilloscope to test point TP (TE) on BD board.
2. Press the "/1 button to turn the unit ON.
3. Put disc (YEDS-18) in to play the number five track.
4. Press the HX button.
5. Check the level B of the oscilloscope's waveform and the A (DC
voltage) of the center of the Traverse waveform.
Confirm the following:
• A/B x 100 = less then ± 22 (%)
• B = 1.3 ± 0.6 Vp-p
1 track jump waveform
E-F Balance (1Track Jump) check
oscilloscope
BD board
TP (FE)
TP (VC) +
–
symmetry
A
B
Within 3 ±1 Vp-p
oscilloscope
BD board
TP (RF)
TP (VC) +
–
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.45 ±0.25 Vp-p
0V
Center of the waveform
B
Symmetry
A (DC voitage)
level : 1.3 ±0.6 Vp-p
oscilloscope
BD board
TP (TE)
TP (VC) +
–
TP
(VC)
TP
(RF)
TP
(TE) TP
(FE1)
TP (FE)
TP
(AGCCON)
SECTION 6
DIAGRAMS
BD board
MIC board
TC-A board
TC-B board
PANEL-FL board
PANEL-VR board
HEADPHONE board
LED board
CD MOTOR board
TABLE SENSOR board
TUNER UNIT
TRANS board MAIN board
FRONT INPUT board
CD-R board
CD-L board PA board
AUDIO board
LEAF SW board
SUB TRANS board (LX7)

HCD-LX7/LX8
18
18
6-2. BLOCK DIAGRAMS
– BD (CD) SECTION –
E
F
A
B
C
D
A
CRF
FF
TE
D
B
E
F
LD
PD
VCC
VC
RF
SUMMING
AMP
FOCUS
ERROR
AMP
TRACKING
ERROR
AMP
LD
DRIVE
Q101 VC
BUFFER
INTEG-
RATOR
RF EQ
AMP
INTEG-
RATOR DIGITAL
PLL
IC101
DIGITAL SERVO
DIGITAL SIGNAL PROCESSOR
SUBCODE
PROCESSOR
SERIAL IN
INTERFACE
SERVO
AUTO
SEQUENCER
SERVO
INTERFACE
OVER SAMPLING
DIGITAL FILTER
D/A
INTERFACE
DIGITAL
OUT
TIMING
LOGIC
ERROR
CORRECTOR
EFM
DEMODULATION
APCLD/PD
AMP
5
7
8
6
16
14 49
51
13
LDON
VC
22
1521
12
11
10
3
IC103
RF AMP
VC
4
VREF
HOLD SW REF
IC102
FOCUS/TRACKING COIL DRIVE
SPINDLE/SLED MOTOR DRIVE
11
12
T+
T–
14
13
F+
F–
TRACKING
COIL
FOCUS
COIL
CH2OUTR
CH2OUTF 5
CH2FIN
6
CH2RIN
2
CH1FIN
3
CH1RIN
23
CH3RIN
24
CH3FIN
25
CH4SIN
27
CH4BIN
20
MUTE
CH1OUTF
CH1OUTR
17
18
SD+
SD–
CH3OUTF
CH3OUTR
M
15
16
SP+
SP–
CH4OUTF
CH4OUTR
M
M102
SLED
MOTOR
M101
SPINDLE
MOTOR
TFDR
TRDR
FFDR
FRDR
SRDR
SFDR
VC
FD
PD
LASER
DIODE
A
C
D
B
E
F
DETECTOR
OPTICAL PICK-UP BLOCK
(KSS-213B/K-N)
LD
POWER
RF AC
ASY1
48
38
42
43
39
41
40
28
26
29
ASY0
ASYMMETRY
CORRECTION
SFDR
MDP
SRDR
33
32 FRDR
FFDR
31
30
42
TRDR
TFDR
SE
CE
TE
FE
RFDC
CE
VC
SLED
PWM
GENERATOR
FOCUS
PWM
GENERATOR
TRACKING
PWM
GENERATOR
PWM
GENERATOR
SLED
SERVO
FOCUS
SERVO
TRACKING
SERVO
SERVO DSP
DIGITAL
CLV
OPERATIONAL
AMPLIFIER
ANALOG
SWITCH
A/D
CONVERTER
16K
RAM
DATA BUS
3rd ORDER
NOISE SHAPER
PWM PWM
CPU
INTERFACE
2
1
3
SQSO
60
D OUT
67
STAO
66
XTA1
8
SENS
20
SCOR
14
XLON
XRST
SQCK
5
DATA
6
XLAT
7
CLOK
9
SCLK
27
SSTP
79
RMUT
80
LMUT
70
LMUT
71
AIN1
72
LOUT1
77
LOUT2
76
AIN2
75
LOUT2
TBL-R
UP SW
TRAY SENS
L OUT
R-CH
TBL-L
HOLD
+5V
SQCK
SCOR
CLOK
XLT
DATA
SENS
SQSO
XRST
DOUT
X101
16.9344MHz
A
MAIN
SECTION
09
S101
LIMIT SW
• SIGNAL PATH
: CD
: Digital out DISC
SENSOR
IC202
IC201
MOTOR DRIVER
3
7
OUT 2
OUT 1
1
IN 2
9
IN 1
M
+5V
M201
TABLE
MOTOR
LED
D201
(DISC No.)
LED SW
Q201
S201
(UP SWITCH)
(Page 20, 21)

HCD-LX7/LX8
19
19
–DECK SECTION –
IC611
R CH
HP101
PB HEAD
(DECK A)
L
R
RV311
PLAYBACK
LEVEL
DECK A
IC601
R CH
L
R
RV301
PLAYBACK
LEVEL
DECK B
31IC602
4
REC/PB
EQOUT
REC BIAS BIAS OSC
T621, Q621, 622
ERASE HEAD
ERASE BIAS
46
48 B IN
A IN
16
PB-A/B
EQIN 38
36
RV301
REC LEVEL
39 RECOUT
BIAS SW
D
M
70
120
DOLBY
TYPE B
+7.5V
Q623
LIN 43
PB
24
18
20
22
40
25
PB OUT
LM ON/
OFF
BIAS ON/OFF
RM ON/OFF
ALC ON/OFF
TC PB L
TC REC L
PB A/B
NORM/HIGH
REC/PB/PASS
BIAS ON/OFF
RM ON/OFF
15 ALC ON/OFF
RELAY
09
B
MAIN
SECTION
LM ON/OFF
NORM/
HIGH
PAS
DOL
PR
REC/PB HEAD
(DECK B)
X
DOLBY NR
IC301
DOLBY NR
HRPE101
RV341
REC
BIAS
32
23
NR ON/
OFF NR ON/OFF
17
S1004
A CrO
2
S1008
B CrO
2
19
A 120/70 B NORM/CROM/
METAL
M
CAP MOTOR
CONTROL
Q336-343
SPEED
CONTROL
Q1001
SWITCH
Q335
RV1001
HIGH
SPEED
RV1002
NORMAL
SPEED
M1
CAPSTAN
MOTOR
CAPM CNT2
CAP M H / L
CAPM CNT1
REEL
DETECT
IC1001 A SHUT
B SHUT
REEL
DETECT
IC1002
S1001 (A PLAY)
+5V
S1002 (B PLAY)
A PLAY
B PLAY
A HALF
B HALF/REC A/REC B
S1003
(A HALF)
+5V
+5V
S1005
(REC A)
S1006
(B HALF)
S1009
(REC B)
•R CH : Same as L ch
•SIGNAL PATH
: PB (DECK A)
: PB (DECK B)
: REC (DECK B)
R CH
CN301
1
3
28 27 26
MS
MS OUT
B TRIG
A TRIG
TRIGGER
MOTOR
CONTROL
Q331-334
A DECK/
B DECK
PLUNGER
•PLUNGER SOLENOID is supplied
as the MECHANICAL BLOCK ASSY.
31, 33
(Page 20, 21)

HCD-LX7/LX8
20
20
–MAIN (1/2) SECTION –
RESET
IC801
SPEANA
MD OUT
J701
L-CH SIG
BBA2
BUS OUT2
REC B2
REC A2
BBB2
VD OUT
6
1
VIDEO 2
IN
IN1
IN3
J804
10
2 3 5
C
B
A
VIDEO
IN
J702
46 45 28
J705
J805
X
12
14
V1, AU
(L IN)
X1
X0
J701
13
10 9
B
A
V2, AU,
L-CH IN
J804
09
46 45
IC181 SELECTOR
IC191
AV SWITCH
PHONO
(L IN)
J701
CD
SECTION
TC PB L
MD (L IN)
69
68
66 IN D2
IN B2
IN A2
IC101
SOUND PROCESSOR 1
IC601
PHONO AMP
65
2
67 IN C2
MIC IN
IN E2
64 IN F2
MUTE
SWITCH
Q804
MUTE
SWITCH
Q803
RESET
SWITCH
Q802
D807
MAIN CONTROL
IC501 (1/2)
6
3
LINE-MUTE
F-RELAY
7
28
34
38
47
45
DBFB-H/L
V-MUTE
SW-MODE
493-LAT
493-DATA
FUNC-SEL1
22AC-CUT
46FUNC-SEL0
48493-MUTE
RESET
7
28
34
38
47
45
46
48
484738
34
37
BUF IN2
SWITCH
Q115
7
SWITCH
Q111
SWITCH
Q112
57
36
39
38
58
L+R 30
MUTE
SWITCH
Q113
VIDEO
OUT
J702
TC REC L
DECK
SECTION
POWER
SECTION MIC-SIG
ST-L
CD-L
D OUT
J701
B
(Page 19)
A
(Page 18)
C
(Page 22,
23)
DECK
SECTION
B
(Page 19)
POWER
SECTION
E
(Page 22, 23)
DISPLAY
SECTION
D
(Page 24)
TC REC L
31
DISPLAY
SECTION
F
(Page 24)
DBFB
F-RELAY
POWER
SECTION
G
(Page 22, 23)
•R CH: Same as L ch
•SIGNAL PATH
: FM
: CD
: PB
: REC
: VIDEO/MD
: Digital out
FM/AM TUNER
TUNER UNIT IS
SUPPLED AS THE
ASSEMBLED
BLOCK
CD
DIGITAL
OUT
D OUT
CD
(L OUT)
CD
(LIN)
IC781
OPTICAL
TRANSMITTING
EXCEPT
LX7/LX8:MX
JW704
LX7/LX8:MX ONLY
33 3234
CLOCKDATALATCH
12
RESET
RESET
SWITCH
Q801
D805
+5v