Sony Walkman MZ-N420D User manual

SERVICE MANUAL
PORTABLE MINIDISC PLAYER
US Model
Canadian Model
E Model
SPECIFICATIONS
MZ-N420D
US and foreign patents licensed from Dolby
Laboratories.
– Continued on next page –
Model Name Using Similar Mechanism MZ-NE410
Mechanism Type MT-MZN710-177
Optical Pick-up Name LCX-5R
Ver 1.0 2004.04
9-877-707-01 Sony Corporation
2004D1678-1 Personal Audio Company
© 2004.04 Published by Sony Engineering Corporation
•SonicStage, OpenMG and the OpenMG
logo, MagicGate, Memory Stick and the
MagicGate Memory Stick logo,
Memory Stick and the Memory Stick
logo, Net MD and the Net MD logo are
trademarks of Sony Corporation.
•Microsoft, Windows, Windows NT and
Windows Media are trademarks or
registered trademarks of Microsoft
Corporation in the United States and /or
other countries.
•IBM and PC/AT are registered
trademarks of International Business
Machines Corporation.
•Macintosh is a trademark of Apple
Computer, Inc. in the United States and/
or other countries.
•MMX and Pentium are trademarks or
registered trademarks of Intel
Corporation.
•All other trademarks and registered
trademarks are trademarks or registered
trademarks of their respective holders.
•™ and ® marks are omitted in this
manual.
Audio playing system
MiniDisc digital audio system
Laser diode properties
Material: GaAlAs
Wavelength: λ= 790 nm
Emission duration: continuous
Laser output: less than 44.6 µW
(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.)
Recording and playback time (when
using MDW-80)
Maximum 160 min. in monaural
Maximum 320 min. in LP4 stereo
Revolutions
Approx. 380 rpm to 2,700 rpm
Error correction
ACIRC (Advanced Cross Interleave Reed
Solomon Code)
Sampling frequency
44.1 kHz
Coding
ATRAC (Adaptive TRansform Acoustic
Coding)
ATRAC3 — LP2/LP4

2
MZ-N420D
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 COMPONENTSWITH SONY PARTSWHOSE PART NUM-
BERS APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLE-
MENTS PUBLISHED BY SONY.
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFÉS PAR UNE MARQUE 0SUR LES
DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES
SONT CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT.
NE REMPLACER CES COMPOSANTS QUE PAR DES PIÈSES
SONY DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL
OU DANS LES SUPPÉMENTS PUBLIÉS PAR SONY.
Modulation system
EFM (Eight to Fourteen Modulation)
Number of channels
2 stereo channels
1 monaural channel
Frequency response
20 to 20,000 Hz ±3 dB
Outputs
i: stereo mini-jack, maximum output level
5 mW + 5 mW, load impedance 24 Ω(US)
5 mW + 5 mW, load impedance 16 Ω(EXCEPT US)
General
Power requirements
One LR6 (size AA) alkaline battery (not
supplied)
Recommended temperature for
check-in/check-out
+5 °C (+41°F) or higher
Dimensions
sMas
Approx. 106 g (3.8 oz) the player only
Approx. 113.3 g (4.0 oz) the player only
Design and specifications are subject to change
without notice.
Supplied accessories
Headphones/earphones (1)
Dedicated USB cable (1)
CD-ROM (SonicStage Ver. 2.0 and
MD Simple Burner Ver. 2.0) (1)*
Battery life 1)
*Do not play a CD-ROM on an audio CD player.
1) When using a new Sony LR6 (size AA) “STAMINA” alkaline dry battery (produced in Japan).
When SP Stereo LP2 Stereo LP4 Stereo
playing2)
2) Measured in accordance with the JEITA (Japan Electronics and Information Technology Industries
Association) standard.
Approx. 42 hours Approx. 48 hours Approx. 56 hours
transferring out audio
data from the computer3)
3) The numbers of tracks that can be checked out differs according to the computer’s operating
environment.
75 tracks (of about
5 minutes each) 300 tracks (of about 5 minutes each) 600 tracks (of about 5 minutes each)
Recordable disc (US and Canadian models only) (1)
Approx. 81 ×28.9 × 74.4 mm (w/h/d) (31/4×
13/16 ×3 in.) without projections.
Left - hand model
Left - hand model
Approx. 81 ×30.7 × 74.4 mm (w/h/d) (31/4×
11/4×3 in.) without projections.
Right - hand model
Right - hand model

3
MZ-N420D
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 dam-
aged by heat.
Flexible Circuit Board Repairing
•Keep the temperature of the soldering iron around 270 ˚C dur-
ing repairing.
•Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
•Be careful not to apply force on the conductor when soldering
or unsoldering.
UNLEADED SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size)
: LEAD FREE MARK
Unleaded solder has the following characteristics.
•Unleaded solder melts at a temperature about 40 ˚C higher than
ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350 ˚C .
Caution: The printed pattern (copper foil) may peel away if the
heated tip is applied for too long, so be careful!
•Strong viscosity
Unleaded solder is more viscous (sticky, less prone to flow) than
ordinary solder so use caution not to let solder bridges occur
such as on IC pins, etc.
•Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.
1. SERVICING NOTES....................................................... 4
2. GENERAL.......................................................................... 5
3. DISASSEMBLY
3-1. Case (Lower) .................................................................. 7
3-2. Upper Panel Section ....................................................... 7
3-3. LCD Module, Button (Control) ..................................... 8
3-4. MAIN Board................................................................... 8
3-5. Mechanism Deck (MT-MZN710-177) .......................... 9
3-6. Set Chassis Assy............................................................. 9
3-7. OP Service Assy (LCX-5R) ......................................... 10
3-8. Holder Assy .................................................................. 11
3-9. DC Motor (Sled) (M602) ............................................. 11
3-10. DC Motor (Over Write Head Up/Down) (M603),
DC SSM18B Motor (Spindle) (M601) ...................... 12
4. TEST MODE.................................................................... 13
5. ELECTRICAL ADJUSTMENTS............................... 18
6. DIAGRAMS
6-1. Block Diagram ............................................................. 38
6-2. Printed Wiring Board - MAIN Board (Side A) ........... 39
6-3. Printed Wiring Board - MAIN Board (Side B) ........... 40
6-4. Schematic Diagram - MAIN Board (1/4) .................... 41
6-5. Schematic Diagram - MAIN Board (2/4) .................... 42
6-6. Schematic Diagram - MAIN Board (3/4) .................... 43
6-7. Schematic Diagram - MAIN Board (4/4) .................... 44
7. EXPLODEDVIEWS
7-1. Case Section ................................................................. 55
7-2. Chassis Section............................................................. 56
7-3. MAIN Board Section ................................................... 57
7-4. Mechanism Deck Section-1 (MT-MZN710-177)........ 58
7-5. Mechanism Deck Section-2 (MT-MZN710-177)........ 59
8. ELECTRICAL PARTS LIST....................................... 60
TABLE OF CONTENTS

4
MZ-N420D
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
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
Never look into the laser diode emission from right above when
checking it for adjustment. It is feared that you will lose your sight.
NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK
(LCX-5R)
The laser diode in the optical pick-up block may suffer electro-
static break-down easily. When handling it, perform soldering
bridge to the laser-tap on the flexible board. Also perform mea-
sures against electrostatic break-down sufficiently before the op-
eration. The flexible board is easily damaged and should be handled
with care.
OPTICAL PICK-UP FLEXIBLE BOARD
SECTION 1
SERVICING NOTES
laser-tap
•In performing the repair with the power supplied to the set, re-
moving the MAIN board causes the set to be disabled.
In such a case, make a solder bridge to short SL802 (OPEN/
CLOSE) on the MAIN board in advance.
upper panel ass
y
MAIN board
FLEXIBLE board
(over write head)
•This set requires the patch data in the nonvolatile memory
(IC852) to be rewritten using the application, when the MAIN
board was replaced. (See page 28)
- MAIN board (Side B) -
SL802
(OPEN/CLOSE)
Handle the FLEXIBLE board (over write head) with care, as it
has been soldered directly to the MAIN board.
In repairing the component side of MAIN board, connect the
FLEXIBLE board (over write head) and the MAIN board with
the lead wires in advance.
Providing the required system environment
The following system environment is required in order to use the SonicStage Ver.2.0/MD
Simple Burner Ver.2.0 software for the MD Walkman.
This software is not supported by the following environments:
OSs other than the indicated above
Personally constructed PCs or operating systems
An environment that is an upgrade of the original manufacturer-installed operating system
Multi-boot environment
Multi-monitor environment
Macintosh
We do not ensure trouble-free operation on all computers that satisfy the system requirements.
The NTFS format of Windows XP/Windows 2000 Professional can be used only with the standard
(factory) settings.
We do not ensure trouble-free operation of the system suspend, sleep, or hibernation function on all
computers.
For Windows 2000 Professional users, install Service Pack 3 or later version before using the
software.
System requirements
Computer IBM PC/AT or Compatible
•CPU: Pentium II 400 MHz or higher (Pentium III 450 MHz or higher
is recommended.)
•Hard disk drive space: 200 MB or more (1.5 GB or more is
recommended) (The amount space will vary according to Windows
version and the number of music files stored on the hard disk.)
•RAM: 64 MB or more (128 MB or more is recommended)
Others
•CD drive (capable of digital playback by WDM)
•Sound Board
•USB port (supports USB (previously USB 1.1))
Operating
System Factory installed: Windows XP Media Center Edition 2004/Windows XP Media Center
Edition/Windows XP Professional/Windows XP Home Edition/
Windows 2000 Professional/Windows Millennium Edition/Windows
98 Second Edition
Display High Color (16bit) or higher, 800 ×600 dots or better (1024 × 768 dots
or better is recommended)
Others •Internet access: for Web registration, EMD services and CDDB
•Windows Media Player (version 7.0 or higher) installed for playing
WMA files
Notes

5
MZ-N420D
SECTION 2
GENERAL This section is extracted from
instruction manual.
This model comes in two designs with different shapes and names for the buttons.
Front of the player
ADisplay window
BVOL (VOLUME ) +* and – button
*
The VOL (VOLUME ) + button has a
tactile dot.
C4-position control key
ENT/NX (ENTER/NX)
(enter/play/pause)*
.and >(search/AMS)
x/CANCEL (stop/cancel)
*
The ENT/NX ( ENTER/NX ) button
has a tactile dot.
DMENU button
EGROUP button
FUSB jack
When connecting to your computer,
connect the dedicated USB cable to
this jack.
GHOLD switch
Hi(headphones/earphones) jack
3
3
5
6
7
4
8
1
2
5
6
7
4
8
1
2
On the following pages of this manual, explanations are given
using the illustration in the top-left of this page.
Back of the player
AOPEN button
BHand strap hole
Use the hole to attach your own strap.
CBattery compartment lid
The display window of the player
ADisc indication
BGroup mode indication
Lights up when group mode is on.
CTrack number display
DBattery level indication
Shows approximate battery condition.
EPlay mode indication
Shows play mode of the MD.
FSOUND indication
GDisc, group, track indication
HCharacter information display
Displays the track names, elapsed
time, etc.
1
3
2
1
2
3
4
5
6
7
8

6
MZ-N420D SECTION 3
DISASSEMBLY
• This set can be disassembled in the order shown below.
3-1. CASE (LOWER)
(Page 7)
3-2. UPPER PANEL SECTION
(Page 7)
3-3. LCD MODULE,
BUTTON (CONTROL)
(Page 8)
3-5. MECHANISM DECK
(MT-MZN710-177)
(Page 9)
3-6. SET CHASSIS ASSY
(Page 9)
3-4. MAIN BOARD
(Page 8)
In order to remove mechanism deck,
please remove MAIN board and upper panel section.
3-7. OP SERVICE ASSY
(LCX-5R)
(Page 10)
3-8. HOLDER ASSY
(Page 11)
3-9. DC MOTOR
(SLED) (M602)
(Page 11)
3-10. DC MOTOR (OVER
WRITE HEAD UP/
DOWN)(M603),
DC SSM18B MOTOR
(SPINDLE) (M601)
(Page 12)
SET

7
MZ-N420D
Note: Follow the disassembly procedure in the numerical order given.
3-1. CASE (LOWER)
3-2. UPPER PANEL SECTION
1 two screws
(M1.4)
2 two screws
(M1.4)
3 Remove the case (lower) in the
direction of the arrow.
5 torsion spring
(pop up-L)
3 two step screws
2 Slide the open slider in the direction of the arrow,
and open the upper panel section.
set chassis assy
torsion spring (pop up-L)
1 flexible board
(CN872)
4 upper panel sectio
n

8
MZ-N420D
3-3. LCD MODULE, BUTTON (CONTROL)
3-4. MAIN BOARD
4 two screws
2 two claws
1 four screws
3 LCD module
6 button (control)
5 open locke
r
case (upper) sub assy
8 MAIN board
6 battery terminal (–)
5 battery terminal board (+
)
2 flexible board (motor)
(CN701)
3 flexible board
(CN872)
7 flexible board (optical pick-up)
(CN501)
1 Remove two solders of the
flexible board (over write head).
4 four screws
(M1.4)

9
MZ-N420D
3-5. MECHANISM DECK (MT-MZN710-177)
3-6. SET CHASSIS ASSY
The portion which projected is removed.
1 step screw (MD)
3 mechanism deck
(MT-MZN710-177)
2
2 two screws
(TP 1.7
× 2.5)
5 set chassis ass
y
4 ground spring (USB)
1 tension spring
(lock)
3 battery case

10
MZ-N420D
3-7. OP SERVICE ASSY (LCX-5R)
4 rack spring
3 screw (M1.4)
1 washer (0.8-2.5)
2 gear (SA)
5 screw (M1.4)
6 thrust detent spring
8 Pull off lead screw.
7
over write head section
OP service assy (LCX-5R)
9 Opening the over write head
toward the direction A , remove the OP service assy
(LCX-5R) toward the direction B .
A
B
Note: Do not open the entire assy forcibly,
when opening the over write head.

11
MZ-N420D
3-8. HOLDER ASSY
3-9. DC MOTOR (SLED) (M602)
2 washer (0.8-2.5)
5 DC motor (sled) (M602)
4 two screws (M1.4)
3 gear (SA)
1 Remove six solders
of the motor flexible board.
5 holder ass
y
4 boss
3 boss
1 convex portion
2 Open the holder assy.

12
MZ-N420D
3-10. DC MOTOR (OVER WRITE HEAD UP/DOWN)(M603), DC SSM18B MOTOR (SPINDLE) (M601)
9 DC SSM18B motor
(spindle) (M601)
8 three tapping screws
2 tapping screw
3 motor cover
6 gear (HA)
4 gear (HB)
5 gear (HC)
DC motor
(over write head up/down)
(M603)
3.15 mm
gear (HA)
Note: Press-fit the gear (HA) up to the position of
the DC motor (over write head up/down)
(M603) as shown below.
7 DC motor (over write head up/down)
(M603)
1 Remove six solders of the
motor flexible board.

13
MZ-N420D
SECTION 4
TEST MODE
Outline
•This set provides the Overall adjustment mode that allows CD
and MO discs to be automatically adjusted when in the test mode.
In this overall adjustment mode, the disc is discriminated be-
tween CD and MO, and each adjustment is automatically ex-
ecuted in order. If a fault is found, the system displays its loca-
tion. Also, the manual mode allows each individual adjustment
to be automatically adjusted.
•Operation in the test mode is performed with the set.
Setting Method ofTest Mode
There are two different methods to set the test mode:
1Short SL803 (TEST) on the MAIN board with a solder bridge
(connect pin <zx. of IC801 to the ground). Then, turn on the power.
Microcomputer
version
display
All off
All lit
Set LCD display
V1.600
009
888
PGM
GP
SOUND 1 2
2In the normal mode, turn on the HOLD . switch. While
pressing the ENTER/NX key press the following order:
[VOLUME +]t[VOLUME +]t[VOLUME --]t[VOLUME --]
t[VOLUME +]t[VOLUME --]t[VOLUME +]t[VOLUME --]
t[GROUP]t[GROUP]
Note: If electrical adjustment (CD and MO overall adjustment) has not
been finished completely, “ERROR” is displayed on LCD of the
set.
Operation in Setting theTest Mode
•When the test mode becomes active, first the display check mode
is selected.
•Other mode can be selected from the display check mode.
•When the test mode is set, the LCD repeats the following dis-
play.
•When the ENTER/NX key is pressed and hold down, the dis-
play at that time is held so that display can be checked.
Releasing theTest Mode
For test mode set with the method 1:
Turn off the power and open the solder bridge on SL803 (TEST)
on the MAIN board.
Note: Remove the solders completely. Remaining could be shorted with
the chassis, etc.
For test mode set with the method 2:
Turn off the power.
IC852
SL803
(TEST)
– MAIN Board (Side B) –

14
MZ-N420D
Configuration ofTest Mode
Manual Mode
Mode to adjust or check the operation of the set by function.
Normally, the adjustment in this mode is not executed.
However, the Manual mode is used to clear the memory, power
supply adjustment, and laser power check before performing au-
tomatic adjustments in the Overall Adjustment mode.
•Transition Method in Manual Mode
1. Set the test mode (see page 13).
2. Press the >to activate the manual mode where the LCD
display as shown below.
3. During each test, the optical pick-up moves outward or in-
ward while the >or .key is pressed for several sec-
onds respectively.
4. Each test item is assigned with a 3-digit item number;
100th place is a major item, 10th place is a medium item, and
unit place is a minor item.
The values adjusted in the test mode are written to the non-
volatile memory (for the items where adjustment was made).
[Manual Mode]
[Servo Adjustment]
[Audio Adjustment]
[Power Supply Adjustment]
[OP Alignment Adjustment]
[Overall Adjustment Mode]
[Sound Skip Check Result Display Mode]
[Key Check Mode]
[Test Mode $Display Check Mode%]
Press the
x/CANCEL key
Press the
x/CANCEL key
Press the . key
Press the MENU or [VOLUME +] key
Press the > key
[Electrical Offset Adjustment]
Power Supply Adjustment
Auto Item Feed
CD Overall Adjustment/
MO Overall Adjustment
[Self-Diagnosis Result Display Mode]
Press the [GROUP] key
Press the
[VOLUME --] key
The key check quits, or open the upper panel
Press the
x/CANCEL key
Press the x/CANCEL key
Set LCD display
Manual
000
x/CANCEL
key
[VOLUME +] key: 100th place of item
number increase.
[VOLUME --] key: 100th place of item
number decrease.
[Major item switching]
[VOLUME +] key: 10th place of item
number increase.
[VOLUME --] key: 10th place of item
number decrease.
[VOLUME +] key: Increases the adjusted
value of the 1st digit
[VOLUME --] key: Decreases the adjusted
value of the 1st digit
[Medium item switching]
x/CANCEL
key
> key
> key
[Minor item switching]
[Adjusted value variation]
[Adjusted value write]
> key: Unit place of item number
increase.
. key: Unit place of item number
decrease.
ENTER/NX key :When adjusted value is
changed:
Adjusted value is written.
When adjusted value is
not changed:
That item is adjusted
automatically.

15
MZ-N420D
5. The display changes a shown below each time the [MENU]
key is pressed.
item number
address
adjusted value
• Address & Adjusted Value Display
Set LCD display
• Jitter Value & Adjusted Value Display
Set LCD display
• Block Error Value & Adjusted Value Display
Set LCD display
• ADIP Error Value & Adjusted Value Display
Set LCD display
• Focus Drive Value & Adjusted Value Display
Set LCD display
• Item Title Display
Set LCD display
C68S16
011
item number
jitter value
adjusted value
0FEJ16
011
item number
block error value
adjusted value
063B16
011
item number
ADIP error value
adjusted value
049A16
011
item number
focus drive value
adjusted value
000F16
011
item number
item title
LrefPw
011
However in the power mode (item number 700’s), only the
item is displayed.
6. Quit the manual mode, and press the x/CANCEL key to re-
turn to the test mode (display check mode).
history code
Total recording time
when error occurred
error display code
Set LCD display
1 0000
0XX
Overall Adjustment Mode
Mode to adjust the servo automatically in all items.
Normally, automatic adjustment is executed in this mode at the
repair.
For further information, refer to “SECTION 5 ELECTRICAL
ADJUSTMENTS” (see page 18).
Self-Diagnosis Result Display Mode
This set uses the self-diagnostic function system in which if an
error occurred during the recording or playing, the mechanism
control block and the power supply control block in the micro-
computer detect it and record its cause as history in the nonvola-
tile memory.
By checking this history in the test mode, you can analyze a fault
and determine its location.
Total recording time is recorded as a guideline of how long the
optical pick-up has been used, and by comparing it with the total
recording time at the time when an error occurred in the self-diag-
nosis result display mode, you can determine when the error oc-
curred.
Clear both self-diagnosis history data and total recording time, if
the optical pick-up was replaced.
•Self-Diagnosis Result Display Mode Setting Method
1. Set the test mode (see page 13).
2. In the display check mode, press the [GROUP] key activates
the self-diagnosis result display mode where the LCD display
as shown below.
3. Then, each time the >key is pressed, LCD display descends
by one as shown below.Also, the LCD display ascends by one
when the .key is pressed.
If the [GROUP] key is pressed with this display, the LCD switches
to the simple display mode.
4. Quit the self-diagnosis result display mode, and press the
x/CANCEL key to return to the test mode (display check mode).
0 XX 1 ****
0 XX N ****
0 XX N1****
0 XX N2****
0 XX R_****
XX : Error code
**** : Total recording time

16
MZ-N420D
• Description of Indication History
History code number Description
1The first error
NThe last error
N1 One error before the last.
N2 Two errors before the last.
R_ Total recording time
• Description of Error Indication Codes
Problem Indication code Meaning of code Simple display Description
No error 00 No error --- No error
01 Illegal access target Adrs Attempt to access an abnormal address
address was specified
Servo system error 02 High temperature Temp High temperature detected
03 Focus error Fcus Disorderedfocusor can notreadan address
04 Spindle error Spdl Abnormal rotation of disc
11 TOC error TOC Faulty TOC contents
TOC error 12 Data reading error Data Data could not be read at SYNC
13 TOC address error Tadr TOC address data error
Power supply system error 22 Low battery LBat Momentary interruption detected
31 Offset error Ofst Offset error
32 Focus error ABCD ABCD Focus error ABCD offset error
offset error
Offset system error 33 Tracking error TE Tracking error Offset error
Offset error
34 X1 tracking error X1TE X1 tracking error Offset error
Offset error
35 MD DATA 2 MD2 MD DATA 2 disc error
disc error
36 Mirror error Mirr Mirror retry over
Reset the Error Display Code
After servicing, reset the error display code.
•Setting Method of Reset the Error Display Code
1. Set the test mode (see page 13).
2. Press the [GROUP] key activates the self-diagnosis result dis-
play mode.
3. To reset the error display code, press the ENTER/NX key
(twice) when the code is displayed (except “R_****”).
(All the data on the 1, N, N1, and N2 will be reset)

17
MZ-N420D
Sound Skip Check Result Display Mode
This set can display the count of errors that occurred during the
recording/playing for checking.
•Setting Method of Sound Skip Check Result Display
Mode
1. Set the test mode (see page 13).
2. Press the [MENU] key or [VOLUME +] key, and the playing
or recording sound skip result display mode becomes active
respectively where the LCD displays the following.
3. When the [MENU] key is pressed, total error count is displayed
on the LCD, and each time the >key is pressed, the dis-
play item moves down by one as shown below. Also, if
the .key is pressed, the display item moves up by one,
then if the [VOLUME +] key is pressed, the display in the record
mode appears.
When the [VOLUME +] key is pressed, total error count is dis-
played on the LCD, and each time the >key is pressed,
the display item moves down by one as shown below.Also, if
the .key is pressed, the display item moves up by one,
then if the [MENU] key is pressed, the display in the play mode
appears.
Total count of play
system errors (hex.)
Total count of record
system errors (hex.)
Set LCD display
P**R**
000
Set LCD display
004
• Cause of Sound Skip Error
Cause of error Description of error
EIB Sound error correction error
Play Stat Decoder status error
Adrs Address access error
BEmp Buffer is empty
BOvr Buffer is full, and sounds were
dumped
Record Bful Buffer capacity becomes less,
and forcible writing occurred
Rtry Retry times over
4. To quit the sound skip check result display mode and to return
to the test mode (display check mode), press the x/CANCEL
key.
• Setting Method of Key Check Mode
1. Set the test mode (see page 13).
2. Press the[VOLUME --] key activates the key check mode.
3. When each key on the set is pressed, its name is displayed on
the set LCD. (Operated position is displayed for 4 seconds
after the slide switch is operated.
Example1: When the >key on the set is pressed:
4. When all keys were checked or if the upper panel is opened,
the key check mode quits and the test mode (display check
mode) comes back.
Set LCD display
FF
004
0 00 P**R**
0 00 EIB **
0 00 Stat**
0 00 Adrs**
0 00 BEmp**
0 00 ######
0 00 P**R**
0 00 BOvr**
0 00 Bful**
0 00 Rtry**
0 00 ######
P**R** : Total play/record errors (hex.)
** : Counter of sound skip check each item (hex.)
###### : 6-digit address where sound was skipped last (hex.)
Playing sound skip
result display Recording sound skip result display

18
MZ-N420D
3. Press the ENTER/NX key once more.
4. Press the x/CANCEL key to quit the manual mode, and
return to the test mode (display check mode).
Temparature Correction
•Adjustment Method ofTemperature Correction
1. Select the manual mode of the test mode, and set the item num-
ber 015 (see page 14).
2. Measure the ambient temperature.
3. Adjust with [VOLUME +] or [VOLUME --] key so that the ad-
justed value (hexadecimal value) becomes the ambient tem-
perature.
(Initial value : 19h = 25˚C, Adjusting range : 80h to 7fh
(–128˚C to +127˚C))
4. Press the ENTER/NX key to write the adjusted value.
Power Supply Manual Adjustment
•Adjustment sequence
Adjustment must be done with the following steps.
1. VC1_LOW (PB) adjustment (item number : 741)
2. VC1_HIGH (REC) adjustment (item number : 742)
3. VC2_LOW adjustment (item number : 743)
4. VC2_HIGH adjustment (item number : 744)
5. REG1 adjustment (item number : 745)
6. REG3_LOW1 adjustment (item number : 747)
7. REG3_LOW2 adjustment (item number : 748)
8. REG3_HIGH adjustment (item number : 749)
9. VREC_LOW (X2 speed) adjustment (item number : 751)
10. VREC_MIDDLE (X4 speed)adjustment (item number : 752)
11. VREC_HIGH(HEAD MOTOR) adjustment (itemnumber : 753)
•Setting Method of Power Supply Manual Adjustment
1. Make sure that the power supply voltage is 1.5V.
2. Select the manual mode of the test mode (see page 14).
3. Set item number.
Note: Power supply adjustment auto item feed mode (page 23) is
available to perform the temperature Correction and Power
Supply Adjustment without entering the manual mode.
NV Reset
•Setting Method of NV Reset
1. Select the manual mode of the test mode, and set item number
021 NV Reset (see page 14).
2. Press the ENTER/NX key.
SECTION 5
ELECTRICAL ADJUSTMENTS
Outline
•In this set, automatic adjustment of CD and MO can be per-
formed by entering the test mode.
However, before starting automatic adjustment, the memory
clear, power supply adjustment and laser power check must be
performed in the manual mode.
Precautions for Adjustment
1. Adjustment must be done in the test mode only.
After adjusting, release the test mode.
2. Use the following tools and measuring instruments.
•Test CD disc TDYS-1
(Part No. : 4-963-646-01)
•SONY MO disc available on the market
•Digital voltmeter
•Laser power meter LPM-8001
(Part No. : J-2501-046-A)
•Thermometer (using the Temperature Correction)
•Personal computer
•USB cable
3. Unless specified otherwise, supply DC 1.5V from battery ter-
minals.
4. Switch position
HOLD .switch..................................... ON
Adjustment Sequence
1. NV Reset (item number: 021)
(EEPROM clear)
r
2. Temperature Correction (item number: 015)
rManual Mode
3. Power Supply Manual Adjustment
r
4. Laser Power Check
r
5. CD Overall Adjustment (item number: 031)
r
6.
MO Overall Adjustment (item number: 034)
r
7. RESUME Clear (item number 043)
r
8. Rewriting the Patch Data
(at replacement of the MAIN board)
r
9. Rewriting the NV values

















Set LCD display
###SCC
021
Set LCD display
ResOK?
021
NV reset (after several seconds)
Set LCD display
Res***
021
Reset!
021
Set LCD display
** : Adjusted value
###S**
015


Manual Mode
Overall Mode

19
MZ-N420D
•Adjustment Method of VC2_LOW
(item number: 743)
1. Connect a digital voltmeter to the TP1905 (VCOUT) on the
MAIN board, and adjust [VOLUME +] key (voltage up) or
[VOLUME --] key (voltage down) so that the voltage becomes
2.30 ±0.01V.
2. Press the ENTER/NX key to write the adjusted value.
Adjustment and Connection Location:MAIN board
(see page 22)
•Adjustment Method of VC2_HIGH
(item number: 744)
1. Connect a digital voltmeter to the TP1905 (VCOUT) on the
MAIN board, and adjust [VOLUME +] key (voltage up) or
[VOLUME --] key (voltage down) so that the voltage becomes
2.55 ±0.01V.
2. Press the ENTER/NX key to write the adjusted value.
Adjustment and Connection Location:MAIN board
(see page 22)
•Adjustment Method ofVC1_LOW (PB)
(item number: 741)
1. Connect a digital voltmeter to theTP1928 (VCO1) on the MAIN
board, and adjust [VOLUME +] key (voltage up) or[VOLUME --]
key (voltage down) so that the voltage becomes 2.35 ±0.05V.
2. Press the ENTER/NX key to write the adjusted value.
Adjustment and Connection Location:MAIN board
(see page 22)
•Adjustment Method ofVC1_HIGH (REC)
(item number: 742)
1. Connect a digital voltmeter to the TP1928 (VCO1) on the
MAIN board, and adjust [VOLUME +] key (voltage up) or
[VOLUME --] key (voltage down) so that the voltage becomes
2.50 ±0.05V.
2. Press the ENTER/NX key to write the adjusted value.
Adjustment and Connection Location:MAIN board
(see page 22)
Set LCD display
** : Adjusted value
AD **
741
digital
voltmete
r
MAIN board
TP1928 (VCO1)
BATT – (GND)
Set LCD display
** : Adjusted value
AD **
742
digital
voltmete
r
MAIN board
TP1928 (VCO1)
BATT – (GND)
Set LCD display
** : Adjusted value
AD **
743
digital
voltmete
r
TP1905 (VCOUT)
BATT – (GND)
MAIN board
Set LCD display
** : Adjusted value
AD **
744
digital
voltmete
r
TP1905 (VCOUT)
BATT – (GND)
MAIN board

20
MZ-N420D
•Adjustment Method of REG1
(item number: 745)
1. Connect a digital voltmeter to the TP1909 (REGO1) on the
MAIN board, and adjust [VOLUME +] key (voltage up) or
[VOLUME --] key (voltage down) so that the voltage becomes
2.05 ±0.01V.
2. Press the ENTER/NX key to write the adjusted value.
Adjustment and Connection Location:MAIN board
(see page 22)
•Adjustment Method of REG3_LOW1
(item number: 747)
1. Connect a digital voltmeter to the TP1907 (REGO3) on the
MAIN board, and adjust [VOLUME +] key (voltage up) or
[VOLUME --] key (voltage down) so that the voltage becomes
1.25 ±0.01V.
2. Press the ENTER/NX key to write the adjusted value.
Adjustment and Connection Location:MAIN board
(see page 22)
•Adjustment Method of REG3_LOW2
(item number: 748)
1. Connect a digital voltmeter to the TP1907 (REGO3) on the
MAIN board, and adjust [VOLUME +] key (voltage up) or
[VOLUME --] key (voltage down) so that the voltage becomes
1.25 ±0.01V.
2. Press the ENTER/NX key to write the adjusted value.
Adjustment and Connection Location:MAIN board
(see page 22)
•Adjustment Method of REG3_HIGH
(item number: 749)
1. Connect a digital voltmeter to the TP1907 (REGO3) on the
MAIN board, and adjust [VOLUME +] key (voltage up) or
[VOLUME --] key (voltage down) so that the voltage becomes
1.25 ±0.01V.
2. Press the ENTER/NX key to write the adjusted value.
Adjustment and Connection Location:MAIN board
(see page 22)
Set LCD display
** : Adjusted value
AD **
745
digital
voltmete
r
TP1909 (REGO1)
BATT – (GND)
MAIN board
Set LCD display
** : Adjusted value
AD **
747
digital
voltmete
r
TP1907 (REGO3)
BATT – (GND)
MAIN board
Set LCD display
** : Adjusted value
AD **
748
digital
voltmete
r
TP1907 (REGO3)
BATT – (GND)
MAIN board
Set LCD display
** : Adjusted value
AD **
749
digital
voltmete
r
TP1907 (REGO3)
BATT – (GND)
MAIN board