Sony HTC-NX300 User manual

SERVICE MANUAL
MINI Hi-Fi COMPONENT SYSTEM
E Model
Chinese Model
SPECIFICATIONS
HTC-NX300
Dolby noise reduction manufactured under license
from Dolby Laboratories Licensing Corporation.
“DOLBY” and the double-D symbol ;are trade-
marks of Dolby Laboratories Licensing Corporation.
HTC-NX300 is the CD player and Tape
Deck section in MHC-NX300AV.
CD
Section
Tape Deck
Section
Model Name Using Similar Mechanism NEW
CD Mechanism Type CDM53E-K3BD37
Base Unit Name Type BU-K3BD37
Optical Pick-up Name KSM-213BFNV/Z-NP
Model Name Using Similar Mechanism HCD-GRX7
Tape Transport Mechanism Type TCM-230AWR2
CD player section
System Compact disc and digital
audio system
Laser Semiconductor laser
(λ=780nm)
Emission duration:
continuous
Laser output Max. .6
µ W*
*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.
Wavelength 780 – 790 nm
Frequency response 20 Hz – 20 kHz (±0.5 dB)
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)
Wavelength 660 nm
Output Level –18 dBm
Tape player section
General
Recording system -track
Dimensions (w/h/d) Applox. 225 x 202 x 3 7
mm
Mass Applox. .6 kg
2-channel stereo
Frequency response 0 – 13,000 Hz (±3 dB),
(DOLBY NR OFF) using Sony TYPE I
cassette
0 – 1 ,000 Hz (±3 dB),
using Sony TYPE II
cassette
Design and specifications are subject to change
without notice.
Ver 1.1 2001.09
9-929-044-12 Sony Corporation
2001I0500-1 Home Audio Company
C2001.9 ShinagawaTec Service Manual Production Group

2
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0OR DOTTED
LINE 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 PUB-
LISHED BY SONY.
TABLE OF CONTENTS
1. SERVICING NOTES ............................................... 3
2. GENERAL
Location of Controls ....................................................... 6
3. DISASSEMBLY ......................................................... 7
4. TEST MODE.............................................................. 14
5. MECHANICAL ADJUSTMENTS....................... 15
6. ELECTRICAL ADJUSTMENTS
TAPE DECK Section ...................................................... 15
CD Section ...................................................................... 18
VIDEO Section ............................................................... 19
7. DIAGRAMS
7-1. Block Diagram – SERVO Section – .............................. 21
7-2. Block Diagram –AUDIO/VIDEO CD Section –.......... 22
7-3. Block Diagram – TAPE DECK Section – ..................... 23
7-4. Block Diagram – POWER SUPPLY Section – ............. 24
7-5. Note for Printed Wiring Boards and
Schematic Diagrams ....................................................... 25
7-6. Printed Wiring Board – BD Board – ............................. 26
7-7. Schematic Diagram – BD Board – ................................ 27
7-8. Schematic Diagram – VIDEO Board (1/2) – ................ 28
7-9. Schematic Diagram – VIDEO Board (2/2) – ................ 29
7-10. Printed Wiring Board – VIDEO Board –....................... 30
7-11. Printed Wiring Boards
– CD MOTOR/SENSOR Section – ................................ 32
7-12. Schematic Diagram
– CD MOTOR/SENSOR Section – ................................ 33
7-13. Printed Wiring Board – AUDIO Board – ...................... 34
7-14. Schematic Diagram – AUDIO Board – ......................... 35
7-15. Printed Wiring Board – LEAF SW Board –.................. 36
7-16. Schematic Diagram – LEAF SW Board –..................... 36
7-17. Printed Wiring Board – MAIN Board – ........................ 37
7-18. Schematic Diagram – MAIN Board (1/2) – .................. 38
7-19. Schematic Diagram – MAIN Board (2/2) – .................. 39
7-20. Printed Wiring Board – POWER Board – ..................... 40
7-21. Schematic Diagram – POWER Board – ........................ 41
7-22. Printed Wiring Boards – PANEL Section – .................. 42
7-23. Schematic Diagram – PANEL Section –....................... 43
7-24. IC Pin Function Description ........................................... 48
8. EXPLODED VIEWS................................................ 57
9. ELECTRICAL PARTS LIST ............................... 64

3
SECTION 1
SERVICING NOTES
The laser diode in the optical pick-up block may suffer electro-
static break-down because of the potential difference generated
by the charged electrostatic load, etc. on clothing and the human
body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The flexible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be focused
on the disc reflective surface by the objective lens in the optical
pick-up block. Therefore, when checking the laser diode emis-
sion, observe from more than 30 cm away from the objective lens.
Flexible Circuit Board Repairing
• Keep the temperature of the soldering iron around 270 ˚C dur-
ing repairing.
• Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
• Be careful not to apply force on the conductor when soldering
or unsoldering.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.
This appliance is classified as a CLASS 1 LASER product.
The CLASS 1 LASER PRODUCT MARKING is located on
the rear exterior.
Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.
The following caution label is located inside the unit.
CAUTION : INVISIBLE LASER RADIATION WHEN OPEN AND
INTERLOCKS DEFEATED. AVOID EXPOSURE TO BEAM.
ADVARSEL : USYNLIG LASERSTRÅLING VED ÅBNING NÅR
SIKKERHEDSAFBRYDERE ER UDE AF FUNKTION. UNDGÅ UDSAETTELSE
FOR STRÅLING.
VORSICHT : UNSICHTBARE LASERSTRAHLUNG, WENN
ABDECKUNG GEÖFFNET UND SICHEREITSVERRIEGELUNG
ÜBERBRÜCKT. NICHT DEM STRAHL AUSSETZEN.
VARO ! :AVATTAESSA JA SUOJALUKITUS OHITETTAESSA OLET ALT-
TIINA NÄKYMÄTTÖMÄLLE LASERSÄTEILYLLE. ÄLÄ KATSO SÄTEESEEN.
VARNING : OSYNLING LASERSTRÅLING NÄR DENNA DEL ÄR ÖPPNAD
OCH SPÄRREN ÄR URKOPPLAD.BETRAKTA EJ STRÅLEN.
ADVERSEL : USYNLIG LASERSTRÅLING NÅR DEKSEL ÅPNES OG
SIKKERHEDSLÅS BRYTES. UNNGÅ EKSPONERING FOR STRÅLEN.
VIGYAZAT ! :A BURKOLAT NYITÁSAKOR LÁTHATATLAN LÉZERSU-
GÁRVESZÉLY
! KERÜLJE A BESUGÁRZÁST !
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)
CN501
SL501
SL502
SL50
3
CN502
IC505
D502
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.

4
POWER SUPPLY DURING SERVICING
• As this set has not own power supply, it does not operate inde-
pendently. Therefore, during servicing, connect it to the Pre-
Main amplifier and Tuner Unit (STR-NX300) of MHC-
NX300AV.
If STR-NX300 are not available, use the Power Feed Jig (PFJ-
1) and Relay Connector Jig.
In this case, after turn on the POWER switch on the Power Feed
Jig, supply power with the following methods.
[Note]
The Power Feed Jig (PFJ-1) is deficient in power to drive this
set.
The details are listed below. For the items with ×marking, use
the STR-NX300.
Operation check Characteristic measurement
Tape Deck af*1
CD section CD a×
SVCD ××
*1: Possible when a flat cable between CN111 (MAIN board) and
CN502 (VIDEO board) is disconnected.
Procedure:
1. Press three buttons of s(DECK B), A(DISC 1),
and s(CD) simultaneously.
2. The G(CD) and S(CD) LEDs blink, and then pressing G
(CD), G/g(DECK A), or G/g(DECK B) button can
make each play possible.
3. Also, the other functions are enabled by pressing two buttons
simultaneously.
A combination of respective functions and buttons is as fol-
lows.
function button
CD AMS – s(DECK A), S(CD)
AMS + s(DECK A), s(CD)
FR s(DECK B), S(CD)
FF s(DECK B), s(CD)
Deck-A REW/AMS – s(CD), g(DECK A)
FF/AMS + s(CD), G(DECK A)
Deck-B REW/AMS – s(CD), g(DECK B)
FF/AMS + s(CD), G(DECK B)
Set
SYSTEM CONTROL termina
l
SYSTEM CONTROL terminal
Connector cable (19P)
Pre-Main AMP
and Tuner Unit
AC IN
Power feed jig
(PFJ-1)
Connector cable (17P) of
attachment to power feed jig
Relay connector jig
(J-2501-174-A)
CD/TC signal
change switch
CN101 (19P)
SYSTEM CONTROL
terminal
system cable
Exclusive cable (15P)
P707, P909 Set
CDP/TC
ST
Connection:

5
Note 1: In cleaning the lens, do not apply an excessive force.
As the optical pick-up is vulnerable, application of
excessive force could damage the lens holder.
Note 2: In cleaning, do not use a cleaner other than exclusive clean-
ing liquid (KK-91 or isopropyl alcohol).
Note 3: Wipe the objective lens spirally from center toward outside.
(See Figure A)
OPTICAL PICK-UP CLEANING
1 Remove the case. (Refer to disassembly page 7)
(Figure A)
3 Open the magnet
ass’y.
4 Cleaning the
optical pick-up.
2 four screws
(BVTP M2.6)

6
SECTION 2
GENERAL
1
2
3
4
5
A
HSs
hH s hH s
AA
123 45
ql
9
0
qa
7
6
8
w;
wa
qkqj
qhqgqfqdqs
• LOCATION OF CONTROLS
– Front Panel –
1G(CD) button and indicator
2S(CD) button and indicator
3s(CD) button
4DISC1 to 5 buttons and indicators
5A(DISC1 to 5) buttons and indicators
6RETURN button
7NEXT button
8PREV button
9g(DECK A) button and indicator
0G(DECK A) button and indicator
qa s(DECK A) button
qs A(DECK A) button
qd DIRECTION button
qf DOLBY NR button
qg HI DUB button
qh CD SYNC button and indicator
qj REC PAUSE/START button and indicator
qk A(DECK B) button
ql s(DECK B) button
w; G(DECK B) button and indicator
wa g(DECK B) button and indicator
3
2
4
5
1
– Rear Panel –
1SYSTEM SELECT switch
2S VIDEO OUT jack
3SYSTEM CONTROL connector
4CD DIGTAL OUT OPTICAL terminal
5VIDEO OUT jack

7
SECTION 3
DISASSEMBLY
CASE
FRONT PANEL SECTION
Note: Follow the disassembly procedure in the numerical order given.
1 screw
(BVTP3
× 10)
2 two screws
(case 3 TP2)
2 two screws
(case 3 TP2)
3 Remove the case
in the arrow
A
direction.
A
6 two screws
(BVTP3
× 10)
5 two screws
(BVTP3
× 5)
1 flat cable (17 core)
(16 cm) (CNS104)
7 claw
1 flat cable (15 core)
(CNS101)
1 flat cable (21 core)
(CN102)
2 connector
(CN106)
8 front panel
section
3 screw (BVTP3 × 5)
4 harness
5 two screws
(BVTP3
× 5)
2 connecto
r
(CN105)

8
CD MECHANISM DECK SECTION
(CDM53E-K3BD37)
TAPE MECHANISM DECK SECTION
(TCM-230AWR2)
3 four screws
(BVTP3 × 10)
1 flat cable (17 core)
(12 cm) (CN112)
4 Remove the CD mechanism deck
section (CDM53E-K3BD37) in
the arrow A direction.
1 flat cable (19 core)
(CN501)
2 connector
(CN713)
A
to fitting base (guide)
ass’y, bracket (chassis)
and magnet ass’y
(page 10)
4 two screws
(BVTP3 × 10)
1 step screw
1 step screw
5 Remove the tape mechanism deck
section (TCM-230AWR2) in the
arrow A direction.
2 spring (eject B)
3 spring (eject A)
6 step screw
8 eject lever (A)
qa bracket (MD A)
qs shield plate
q; bracket (MD B)
7 eject lever (B
)
6 step screw
9 two screws
(BVTT 2.6 × 6)
A

9
CD BASE UNIT (BU-K3BD37)
VIDEO BOARD
4 CD base unit
(BU-K3BD37)
2 compression spring
(silver)
1 two screws
(PTPWH M2.6)
1 two screws
(PTPWH M2.6)
3 compression spring
(black)
3 flat cable (15core)
(CN713)
6 screw
(BVTT3 × 5)
8 screw
(BVTT3 × 5)
5 SVCD shield (B)
9 two screws
(BVTP3 × 8)
0 VIDEO board
6 screw
(BVTT3 × 5)
6 screw
(BVTT3 × 5)
1 two screws
(BVTT3 × 5 (S))
2 ground plate
4 three screw
(BVTT3 × 8)
7 SVCD shield (U)

10
FITTING BASE (GUIDE) ASS’Y, BRACKET (CHASSIS) AND
MAGNET ASS’Y
MAIN BOARD
7 four screws
(BVTP M2.6)
2 four screws
(BVTP M2.6)
5 bracket
(chassis)
4 three screws
(BVTP M2.6)
4 two screws
(BVTP M2.6)
6 connector
(CN710)
1 two connectors
(CN709, 715)
3 fitting base
(guide) ass’y
8 magnet ass’y
from CD mechanism
deck section
(CDM53E-K3BD37)
(page 8)
2 three screws
(BVTP3
× 10)
2 four screws
(BVTP3
× 10)
7 two screws
(BVTP3
× 8)
6 connector
(CN108)
6 connector
(CN109)
6 connector
(CN107)
9 Remove the MAIN board
in the arrow
A direction.
4 connection cord
(CN101)
5 back panel
3 cover
(connector)
A
8 two PC board
holders
1 connector
(CN505)

11
TRAY (SUB)
pulley (LD)
stocker
section
tray (sub)
pulley (mode)
slider (selection)
1 Rotating the pulley (LD), shift the slider (selection) in the arrow A direction.
2 Rotating the pulley (mode) in the arrow direction, adjust the tray (sub) to be removed.
3 Rotating the pulley (LD), shift the slider (selection) in the arrow B direction.
4 Rotating the pulley (mode) in the arrow direction, remove the tray (sub) to be removed.
A
B
CHASSIS (MOLD B) SECTION, STOCKER SECTION AND
SLIDER (SELECTION)
Note: In mounting the parts, refer to page 12 and 13.
5 stocker
section
4 two step
screws
4 two step screws
3 gear (eject)
2 chassis (mold B) section
Note: Rotating the pulley (LD),
shift the slider (selection
)
to the left.
9 compression
spring
7 slider (selection)
8 washer
6 two screws
(PTPWH M2.6)
1 three screws
(BVTP M2.6)
pulley (LD)

12
GEARS INSTALLATION
1 Slide the slider (U/D)
fully in the arrow
direction.
3 gear (gear B)
2 gear (U/D slider)
4 gear (gear A)
Adjust the gear (gear B) with the
portion A as shown.
Adjust the gear so that it meshes with
the bottom tooth of slider (U/D) gear,
as shown.
portion A
slider (U/D) gear linearly
gear
(gear B)
Adjust so as to be aligned with
gear (B) linearly, as shown.
SLIDER (SELECTION) INSTALLATION
portion A
2 gear (chucking)
6 two screws
(PTPWH M2.6)
5 washer
3 convex portion of
slider (selection)
4 compression spring
7 Insert the slider (selection)
into the portion A.
1 rotary encoder
rotary encoder
Align with the slot of
rotary encoder.
align marking
gear (chucking)
Insert a convex portion into
a groove of gear (chucking).

13
STOCKER SECTION INSTALLATION
2 portion A of tray (sub)
1 stocker section
3 two step screws
3 two step screws
Hook the portion A of tray (sub)
to the slider (selection).
potion A
of tray (sub) sticking of
slider (selection)
CHASSIS (MOLD B) SECTION INSTALLATION
3 three screws
(BVTP M2.6)
2 Insert the gear (eject)
under the gear (LD
deceleration).
1 Insert the portion A of
chassis (mold B) sectio
n
into the portion B of
slider (selection).
gear (LD deceleration)
portion A
portion B of
slider (selection)

14
SECTION 4
TEST MODE
[LED All Lit, Key Check Mode]
Procedure:
1. Press the ?/1button to turn the power ON.
2. Press three buttons of s(DECK B), A(DISC 1), and
[DISC 5] simultaneously.
3. LEDs are all turned on.
Press the G(CD) button, and the key check mode is activated.
LEDs are all OFF.
4. When a button is pressed, the LED near the pressed button
blinks or lights up.
Also, if all buttons are pressed, all LEDs light up (not blink).
5. To release from this mode, press three buttons in the same
manner as step 2, or remove the power cord.
[CD Delivery Mode]
• This mode moves the optical pick-up to the position durable to
vibration. Use this mode when returning the set to the customer
after repair.
Procedure:
1. Press the ?/1button to turn the power ON.
2. Press the s(DECK B) and [DISC 1] buttons simultaneously.
3. A message “LOCK” is displayed on the liquid crystal display
of the STR-NX300, and the CD delivery mode is set.
[Tape DeckTest Mode]
(In case of connected to the STR-NX300)
• If connected to the STR-NX300, the mode also acts as the STR-
NX300 amplifier test mode.
Procedure:
1. Press the ?/1button to turn the power ON.
2. Pressthree buttonsof s(DECK B), A(DISC1),and S(CD)
simultaneously.
3. On liquid crystal display of the STR-NX300, the disc calen-
dar blinks, and “ALC OFF” is displayed, then the function
which was set before the test mode became active is displayed.
4. The automatic level control of the tape deck is in OFF status,
but while the s(CD) and [REC PAUSE/START] buttons are
pressed during recording, automatic level control goes in ON
status.
[Tape DeckTest Mode]
(In case of connected to the power feed jig)
Procedure:
1. Turn on the Power switch on the power feed jig.
2. Press three buttons of s(DECK B), A(DISC 1),
and s(CD) simultaneously.
3. The G(CD) and S(CD) LEDs blink, and then pressing G
(CD), G/g(DECK A), or G/g(DECK B) button can
make each play possible.
4. Also, the other functions are enabled by pressing two buttons
simultaneously.
A combination of respective functions and buttons is as fol-
lows.
function button
CD AMS – s(DECK A), S(CD)
AMS + s(DECK A), s(CD)
FR s(DECK B), S(CD)
FF s(DECK B), s(CD)
Deck-A REW/AMS – s(CD), g(DECK A)
FF/AMS + s(CD), G(DECK A)
Deck-B REW/AMS – s(CD), g(DECK B)
FF/AMS + s(CD), G(DECK B)
Note: Check that CD/TC signal change switch of relay connector jig is
set to the TC position.
[VIDEO CD Color-bars Mode]
On this mode, the data of the color-bars signal as a picture signal
and the 1 kHz sine wave signal as a sound signal are output by the
mechanism controller (IC505) for the 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) (STR-NX300) using an oscillo-
scope.
Procedure:
1. Short the both ends of the land of SL503 of theVIDEO board.
2. Turn the power on. Press the [FUNCTION] button to select
CD.
3. The color-bars appears when the CD is in stop status, and it
disappears when the CD goes in play status.
4. After measuring, remove the lead wire connected.
– VIDEO board (Side B) –
CN501
SL501
SL502
SL50
3
CN502
IC505

15
SECTION 5
MECHANICAL ADJUSTMENTS SECTION 6 ELECTRICAL ADJUSTMENTS
Precaution
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback heads pinch rollers
erase head rubber belts
capstan idlers
2. Demagnetize the record/playback head with a head demagne-
tizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power sup-
ply voltage unless otherwise noted.
Torque Measurement
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
(0.03 – 0.08 oz • inch)
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
(0.03 – 0.08 oz • inch)
71 to 143 g • cm
(0.99 – 1.99 oz • inch)
100 g or more
(3.53 oz or more)
100 g or more
(3.53 oz or more)
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
1. Demagnetize the record/playback head with a head demagne-
tizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
parts adjust.
4. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
5. The adjustments should be performed in the order given in
this service manual. (As a general rule, playback circuit ad-
justment should be completed before performing recording
circuit adjustment.)
6. The adjustments should be performed for both L-CH and R-
CH.
7. Switches and controls should be set as follows unless other-
wise specified.
8. Set to the DOLBY NR OFF.
9. Set to the test mode. (See page 14)
10. When using the PFJ-1, disconnect a flat cable between CN111
(MAIN board) and CN502 (VIDEO board).
• Test Tape
Record/Playback Head Azimuth Adjustment
Note: Perform this adjustments for both decks
Procedure:
1. Mode: Playback
0 dB=0.775 V
TAPE DECK SECTION
DECK A DECK B
AUDIO OUT jac
k
+
–
level meter
test tape
P-4-A100
(10 kHz, –10 dB)
PFJ-1
or
STR-
NX300
set
Tape Signal Used for
P-4-A100 10 kHz, –10 dB Azimuth Adjustment
WS-48B 3 kHz, 0 dB Tape Speed Adjustment
P-4-L300 315 Hz, 0 dB Level Adjustment

16
Tape Speed Adjustment DECK B
• Execute only if connected to the STR-NX300
Mode: Playback
1. Insert the WS-48B into the deck B.
2. Press the G(DECK B) button.
3. Press the [HI-DUB] button in playback mode.
Then at HIGH speed mode.
4. Adjust RV1001 on the LEAF SW board do that frequency
counter reads 6,000 ± 180 Hz.
5. Press the [HI-DUB] button.
Then back to NORMAL speed mode.
6. Adjust RV1002 on the LEAF SW board so that frequency
counter reads 3,000 ± 90 Hz.
Adjustment Location: LEAF SW board
Sample value of Wow and Flutter: 0.3% or less W.RMS (JIS)
(WS-48B)
Playback level Adjustment DECK A DECK B
Procedure:
Mode: Playback
Deck A is RV311 (L-CH) and RV411 (R-CH), Deck B is RV301
(L-CH) and RV401 (R-CH) so that adjustment within specified
value as follows.
Specified Value:
AUDIO OUT jack PB level: 301.5 to 338.3 mV (–8.2 to –7.2
dB) level
difference between the channels: within ± 0.5 dB
Adjustment Location: AUDIO board
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
3. Mode: Playback
4. Repeat step 1 to 3 in playback (REV) mode.
5. After the adjustments, apply suitable locking compound to the
pats adjusted.
Adjustment Location:Playback Head (DeckA).
Record/Playback/Earth Head (Deck B).
Screw
position
L-CH
peak
within
1dB
Output
level
L-CH
peak R-CH
peak
within
1dB
Screw
position
R-CH
peak
test tape
P-4-A100
(10 kHz, –10 dB) oscilloscope
AUDIO OUT (R) jack
L-CH
R-CH
VH
waveform of oscilloscope
in phase 45 ° 90 ° 135 ° 180 °
good wrong
AUDIO OUT (L) jack
L-CH
R-CH
PFJ-1
or
STR-
NX300
set
forward
reverse
Open the cassette holder
and unhock six claws of
the sub panel (TC2)
with tweezers or something,
then remove the sub panel (TC2).
+
–
AUDIO OUT jack
test tape
WS-48B
(3 kHz, 0 dB) frequency counter
set STR-
NX300
+
–
test tape
P-4-L300
(315 Hz, 0 dB) level meter
AUDIO OUT jac
k
PFJ-1
or
STR-
NX300
set

17
REC Bias Adjustment DECK B
Procedure:
1. Mode: Record
2. Mode: Playback
3. Confirm playback the signal recorded in step 1 become speci-
fied value as follows.
If these values are out of specified value, adjust the RV341
(L-CH) and RV441 (R-CH) on the AUDIO board to repeat
steps 1 and 2.
Specified value: Playback output of 315 Hz to playback
output of 10 kHz: ± 0.5 dB
Adjustment Location: AUDIO board
REC Level Adjustment DECK B
Procedure:
1. Mode: Record
2. Mode: Playback
3. Confirm playback the signal recorded in step 1 become speci-
fied value as follows.
If these values are out of specified value, adjust the RV301
(L-CH) and RV351 (R-CH) on the MAIN board to repeat steps
1 and 2.
Specified value:
AUDIO OUT jack PB level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location: MAIN board
– MAIN BOARD (Conductor Side) –
– AUDIO BOARD (Component Side) –
– LEAF SW BOARD (Component Side) –
RV401
RV301 RV341 RV311 RV411
IC602 CN601
LRRL
     
RV441
PB LEVEL
– DECK B –
REC BIAS
LR
  
PB LEVEL
– DECK A –
TAPE SPEED
RV1002 RV1001
(NORMAL) (HIGH)
CN1001
         
attenuator
1) 315 Hz
2) 10 kHz 50 mV (–23.8 dB)
PFJ-1
or
STR-
NX300
AUDIO IN jack



600 Ω
blank tape
CN-123
AF OSC
set
+
–
recorded
portion level meter
AUDIO OUT jack
PFJ-1
or
STR-
NX300
set
attenuator
315 Hz, 50 mV (–23.8 dB)
AUDIO IN jack
600
Ω
blank tape
CN-123
AF OSC
PFJ-1
or
STR-
NX300 set
+
–
recorded
portion level meter
AUDIO OUT jack
PFJ-1
or
STR-
NX300
set
RV351
(R-CH)
RV301
(L-CH)
IC301
REC
LEVEL









CN3011
3

18
Note:
1. CD Block is basically designed to operate without adjustment. There-
fore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10 MΩimpedance.
4. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.
5. Use the following extension cables and relay connector.
• Extension cable (19P) (Part No. J-2501-011-B)
Relay connector (Part No. J-2501-167-A)
(BD board CN101 to VIDEO board CN501)
• Extension cable (17P) (with connector) (Part No. J-2501-167-A)
(CONNECTOR board CN701 to MAIN board CN112)
6. Perform measurement by connecting to the STR-NX300.
1. S-CURVE CHECK
Procedure:
1. Connect oscilloscope to TP (FEO).
2. Connect between TP (FEO) and TP (VC) by lead wire.
3. Connect betweenTP (AGCCON) andTP (GND) by lead wire.
4. Turn the power ON.
5. Load a disc (YEDS-18) and turn the power ON again and ac-
tuate the focus search. (Actuate the focus search when disc
tray is moving in and out)
6. Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 2.4
± 0.7 Vp-p.
S-curve waveform
7. 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.
CD SECTION
A
B
symmetry
within 2.4
± 0.7 Vp-p
+
–
BD board
TP (RF)
TP (VC)
oscilloscope
VOLT/DIV: 200 m
V
TIME/DIV: 500 ns
level:
1.2
± 0.2 Vp-p
+
–
BD board
TP (FEO)
TP (VC)
oscilloscope
2. RF LEVEL CHECK
Procedure:
1. Connect oscilloscope to TP (RF).
As TP (RF) and TP (VC) are located at the edge of board, clip
them together with the board using alligator clips.
2. Turn the power ON.
3. Load a disc (YEDS-18) and playback.
4. Confirm that oscilloscope waveform is clear and check RF
signal 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

19
Connecting points:
– BD BOARD (Side B) –
IC102
TP
(VC)
TP
(RF)
TP
(FEO)
IC101
TP (FEI)
TP
(TEO)
TP
(GND)
TP
(AGCCON)
IC103
– MAIN BOARD (Conductor Side) –
IC101
SL101
(ADJ)
VIDEO SECTION
Note:
1. Perform measurement by connecting to the STR-NX300.
Frequency Adjustment
Connection:
Procedure:
1. Connect the frequency counter to TP (27 MHz) on VIDEO
board.
2. Turned power switch on.
3. Press the [FUNCTION] button to select the CD.
4. Adjust CT503 on the VIDEO board so that the frequency
counter reading 27.0 MHz ± 80 Hz at stop status.
Adjustment Location:
– VIDEO Board (Side B) –
+
–
TP (27 MHz)
VIDEO board frequency counter
TP
(GND)
CT503
VIDEO
Frequency
Adjustment
TP
(27 MHz)
CN501
SL501
SL502
SL503
CN502
IC505
D502

20
MEMO