Material: GaAlAs
Wavelength: λ = 780 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.)
D-A conversion
1-bit quartz time-axis control
Frequency response
20 - 20 000 Hz
+1–2
dB (measured by JEITA CP-
307)
Output (at 4.5 V input level)
Line output (stereo minijack)
Output level 0.7 V rms at 47 kΩ
Recommended load impedance over 10 kΩ
Headphones (stereo minijack)
Approx. 5 mW + Approx. 5 mW at 16 Ω
(Approx. 0.5 mW + Approx. 0.5 mW
at 16
Rechargeable batteries8892
NC-6WM and
external battery case
(two alkaline batteries***)
*Measured value by the standard of JEITA
(Japan Electronics and Information Technology
Industries Association).
** Charging time varies depending on how the
rechargeable battery is used.
*** When using Sony alkaline batteries LR6 (SG)
(produced in Japan)
Operating temperature
5°C - 35°C (41°F - 95°F)
Dimensions (w/h/d) (excluding
projecting parts and controls)
Approx. 135.0 × 18.2 × 135.0 mm
(5
3
⁄8 × 23⁄32 × 5
3
⁄8 in.)
Mass (excluding accessories)
Approx. 172 g (6.1 oz)
Supplied accessories
For the area code of the location in which you
purchased the CD player, check the upper left side
of the bar code on the package.
AC power adaptor (1)
Headphones/earphones with remote control (1)
Rechargeable batteries (2)
Battery carrying case (2)
Carrying pouch (1)
External battery case (1)
AC plug adaptor (1)*
1
*1Supplied with E33 and Tourist models
Design and specifications are subject to change
without notice.
• Abbreviation
E13: 220 - 230 V AC area in E model
E33: 100 - 240 V AC area in E model
SERVICE MANUAL
Ver 1.3 2003.11
SPECIFICATIONS
US Model
Canadian Model
AEP Model
UK Model
E Model
Austr alian Model
Chinese Model
Tourist Model
Model Name Using Similar Mechanism NEW
CD Mechanism TypeCDM-3325ES
Optical Pick-up NameDAX-25E
9-873-379-04Sony Corporation
2003K05-1Personal Audio Company
C 2003.11Published by Sony Engineering Corporation
5-5. Printed W iring Board ...................................................... 14
5-6. Schematic Diagram – MAIN Board (1/3) – .................. 15
5-7. Schematic Diagram – MAIN Board (2/3) – .................. 16
5-8. Schematic Diagram – MAIN Board (3/3) – .................. 17
5-9. IC Pin Function Description ........................................... 18
On AC power adaptor
• Use only the AC power adaptor supplied or
recommended in “Accessories (supplied/
optional).” Do not use any other AC power
adaptor. It may cause a malfunction.
Polarity of the plug
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.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation exposure.
7.ELECTRICAL PARTS LIST ............................... 28
This appliance is classified as a CLASS 1 LASER product.
The CLASS 1 LASER PRODUCT MARKING is located on
the rear exterior.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED
LINE WITH MARK 0 ON THE SCHEMATIC DIAGRAMS
AND IN THE PARTS LIST ARE CRITICAL TO SAFE
OPERATION. REPLACE THESE COMPONENTS WITH
SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANU AL OR IN SUPPLEMENTS PUBLISHED BY SONY.
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFIÉS P AR UNE MARQUE 0
SUR LES DIAGRAMMES SCHÉMA TIQUES ET LA LISTE
DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ
DE FONCTIONNEMENT. NE REMPLACER CES COMPOSANTS QUE PAR DES PIÈCES SONY DONT LES
NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY.
2
SECTION 1
SERVICING NOTES
D-EJ855
About CD-Rs/CD-RWs
This CD player can play CD-Rs/CD-RWs recorded in the CD-D A
format*, but playback capability may vary depending on the quality of the disc and the condition of the recording device.
* CD-DA is the abbreviation for Compact Disc Dig ital Audio. It is
a recording standard used for the Audio CDs.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic breakdown because of the potential difference generated by
the charged electrostatic load, etc. on clothing and the human body .
During repair, pay attention to electrostatic breakdown and also
use the procedure in the printed matter which is included in the
repair parts.
The flexible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be focused
on the disc reflective surface by the objective lens in the optical
pick-up block. Therefore, when checking the laser diode emission, observe from more than 30 cm away from the objecti ve lens.
BEFORE REPLACING THE OPTICAL PICK-UP BLOCK
Please be sure to check thoroughly the parameters as par the “Optical Pick-Up Block Checking Procedures” (Part No.: 9-960-027-
11) issued separately before replacing the optical pick-up block.
Note and specifications required to check are given below.
• FOK output: IC601 yg pin
When checking FOK, remove the lead wire to disc motor.
• RF signal P-to-P value: 0.4 to 0.6 Vp-p
LASER DIODE AND FOCUS SEARCH OPERATION
CHECK
During normal operation of the equipment, emission of the laser
diode is prohibited unless the upper lid is closed while turning ON
the S804. (push switch type)
The following checking method for the laser diode is operable.
• Method:
Emission of the laser diode is visually checked.
1. Open the upper lid.
2. With a disc not set, turn on the S801 with a screwdri ver having
a thin tip as shown in Fig.1.
3. Press the
4. Observing the objective lens, check that the laser diode emits
light.
When the laser diode does not emit light, automatic power
control circuit or optical pickup is faulty.
In this operation, the objective lens will move up and down 4
times along with inward motion for the focus search.
> N button.
S804
detection lever
detection lever
MAIN board
Fig. 1 Method to push the S804
3
D-EJ855
SERVICE MODE
In the Service mode, this set can check the following.
[HOLD] switch (S801) .......................... OFF
•
[G PROTECTION] switch (S803) ....... 1
3) Short the solder bridge at the SL807 (TEST) on the MAIN
board (see Fig. 2).
4) Turn the power on.
– MAIN Board (Component Side) –
R811
D803
C809
R807
SL807
(TEST)
R812
FB803
VDR8
C805
+
C440
+
C806
C807
C804
C464
SL806
(OPEN)
R808
C810
A
C811
K
A
D805
R813
2. Operation in Service Mode
When the Service mode is set, the LCD on the remote commander
displays the following.
Remote commander LCD display
Microcomputer
version display
All lit
Service mode
VD101
888
DDDD
BASS12
3. Operation of Buttons and Knobs in Service Mode
The following operation can be checked by operating the buttons
and knobs on the set and remote commander.
3-1 . Case without Setting a CD
> N / . buttons on the set and > N / . knobs on
•
remote commander
Optical pick-up movement (outward or inward)
Tracking/sled servo off
Note: Do not look directly at the laser beam from the optical pick-up.
Do not move forcibly the optical pick-up exceeding the most-outside or most-inside track.
3-2 . Case with Setting a CD
Cheking method:
1) Make sure that the power is not turned on.
2) Leave a solder bridge of the SL807 (TEST) on the MAIN board
shorted.
3) Turn the power on, and then set a CD and play it with the X
button on the remote commander.
Fig. 2
Remote Commander LCD display
0000
(play mode)
• x button on the set and remote commander
All servos (focus/tracking/sled) off
•> N / . buttons on the set and > N / . knobs on
remote commander
Optical pick-up movement (outward or inward)
Tracking/sled servo off
•[PRT/ENT] button on remote commander
Tracking gain up mode
Remote Commander LCD display
Up0000
(For the rest, turn the power off and then turn it on again)
•[VOL +] / [VOL --] buttons on the set and [VOL +] / [VOL --]
knobs on remote commander
2-step volume setting
•[PLAYMODE] button on remote commander
CL V speed becomes 1 to 4 times each time the button is pr essed
Tracking/sled servo on
4
Remote Commander LCD display
D-EJ855
010001
040004
(For the rest, turn the power off and then turn it on again)
•[SOUND] button on remote commander
Servo auto adjustment
4.Service Mode Releasing Method
To release the service mode, perform as follows.
1) Turn the power off.
2) Open the solder bridge at the SL807 (TEST) on the MAIN
board.
Note: Remove the solder completely.
5.Error Rate Check Display
The C1 error rate check display mode becomes active if the following operation is performed during the operation in the normal
mode.
1) Turn the power off, and cancel other service operations.
2) Turn the power on, and then set a CD and play it with the X
button on the remote commander.
Remote Commander LCD display
(1 time)
(4 times)
0000
3) Press the [SOUND] button on the remote commander to make
automatic adjustment.
4) Press the [PLAY MODE] button on the remote commander.
Remote Commander LCD display
010001
5) Press the [DISPLAY] button on the remote commander, and
the C1 error rate display will be activated and the LCD on the
remote commander will display as follows.
Remote Commander LCD display
Er****
Note: In the play state, press the [SOUND] button on the remote com-
mander before pressing the [PLAY MODE] b utton. Wrong order of
button operations will result in very large Er**** value.
6) Turn the power off.
7) Open the solder bridges at the SL807 (TEST) on the MAIN
board.
Note: Remove the solder completely.
**** value
0000 to 0099: OK
more than 0100 : NG
5
D-EJ855
SECTION 2
GENERAL
This section is extracted from
instruction manual.
Getting started
Locating the controls
For details, see pages in parentheses.
CD player (front)
1 EXT BATT (external battery)/
DC IN 4.5 V (external power
input) jack (pages 7, 19, 21)
2 LINE OUT (OPTICAL) jack
(page 17)
3 VOL (volume) +*/– buttons
(page 8)
4 x (stop) /CHARGE button•
CHARGE lamp
(pages 8, 15, 16, 19)
5 .(AMS/search)•> N*
(AMS/search/play) buttons
(pages 7, 8, 12)
6 i (headphones) jack
(page 7)
7 OPEN switch
(page 7)
CD player (inside)
8 AVLS switch
(page 15)
9 G-PROTECTION
switch
(page 13)
q; Battery
compartment
(page 19)
*The button has a tactile dot to help you operate the CD player by touch.
VOL +/–: Pull the control in the direction of the
arrow, and then turn it toward + or –. (page 8)
qg Clip
qh DISPLAY
button
(pages 13, 14)
qj PLAY MODE
button
(pages 10 - 12)
qk RPT (repeat)/ENT
(enter) button
(pages 10 - 12)
qf x (stop) button
(pages 8, 16)
ql HOLD switch
(page 15)
w; i (headphones) jack
(page 7)
wa X (pause) button
(page 8)
ws SOUND button
(page 14)
Note
Use only the supplied remote control. You cannot
operate this CD player with the remote control
supplied with other CD players.
Getting started
5
Using the carrying pouch
You can carry your player and its battery case together using the supplied carrying pouch. Insert
them into the proper places in the pouch as illustrated below.
6
6
• This set can be disassembled in the order shown below.
3
guide (L)
2
screw
(M1.4)
4
screw
(M1.4)
1
Open the upper lid (M) sub assy.
6
Remove the upper lid (M) sub assy
in the direction of arrow
A
.
A
5
guide (R)
!
@
Note: To install screws, tighten them with 0.4 kg/cm2 of torque.
(If tighten them too hard, portion
!
may get cracked.)
3-1.DISASSEMBLY FLOW
3-2. UPPER LID (M) SUB ASSY
3-3. CABINET (UPPER) SUB ASSY
3-4. MAIN BOARD,
SECTION 3
DISASSEMBLY
SET
(Page 7)
(Page 8)
OPTICAL PICK-UP SECTION (CDM-3325ES)
(Page 8)
D-EJ855
Ver 1.1
Note: Follow the disassembly procedure in the numerical order given.
3-2.UPPER LID (M) SUB ASSY
7
D-EJ855
)
n
3-3.CABINET (UPPER) SUB ASSY
knob (GPRO)
3
1
screw (B2)
4
cabinet (upper) sub assy
Note: On installation of cabinet (upper) sub assy,
adjust the position of two switches
(S802, S803) and two knobs (GPRO).
Hold up both the main board and the
optical pick-up section at once, and remove
them from the cabinet (lower) assy.
Note: Handle the flexible board with care whe
you hold up the optical pick-up section.
SECTION 4
p
ELECTRICAL CHECK
D-EJ855
The CD section adjustments are done automatically in this set.
In case of operation check, confirm that focus bias.
Precautions for Check
1. Perform check in the order given.
2. Use YEDS-18 disc (P art No.: 3-702-101-01) unless otherwise
indicated.
3. Power supply voltage requirement: DC4.5 V in DC IN jack.
(J401)
VOLUME: Minimum
AVLS switch: NORM
HOLD switch: OFF
G•PROTECTION switch : 1
Connecting and Checking Location:
– MAIN Board (Component Side) –
TP418
(GND)
J301
LINE OUT
(OPTICAL)
TP601 (RF)
Focus bias Check
Condition:
• Hold the set in horizontal state.
Connection:
MAIN board
TP601 (RF)
TP418 (GND)
2 k
Ω
oscilloscope
(AC range)
+
–
Procedure:
1. Connect the oscilloscope to the test points TP601 (RF) and
TP418 (GND) on the MAIN board.
2. Set a disc. (YEDS-18)
3. Press the > N button.
4. Check the oscilloscope waveform is as shown below.
A good eye pattern means that the diamond shape (◊) in the
center of the waveform can be clearly distinguished.
RF Signal reference Waveform (Eye Pattern)
VOLT/DIV : 100 mV (With the 10:1 probe in use)
TIME/DIV : 500 ns
OPTICAL
PICK-UP
BLOCK
DAX-25E
R601
R603
R602
C601
C603
D403
CN503
1
15
R604
KA
R410
C604
C448
606
605
R305
C404
C449
+
R489
12
1
VDR304
C301
IC404
VDR303
RF level
0.4 to 0.6 Vp-
To watch the eye pattern, set the oscilloscope to AC range and
FB201
VDR201
VDR301
R303
C202
FB301
R202
R304
R201
VDR101
24
FB101
R469
R101
C452
C453
C102
C454
13
R102
55
increase the vertical sensitivity of the oscilloscope for easy watching.
5. Stop revolving of the disc motor by pressing the x button.
99
D-EJ855
SECTION 5
DIAGRAMS
5-1.BLOCK DIAGRAM – MAIN Section (1/2) –
DETECTOR
A
(Page 12)
B
(Page 12)
C
(Page 12)
OPTICAL PICK-UP BLOCK
LASER DIODE
PD
LD
(FOCUS)
2-AXIS
DEVICE
(TRACKING)
M902
(SPINDLE)
V
U
W
VG
• SIGNAL PATH
: CD PLAY (ANALOG OUT)
: CD PLAY (OPTICAL OUT)
A
B
RF
E
F
VCC
DAX-25E
PD
OPSTB
OPGSW
LD
A
B
RF
E
F
VCPU B+
M901
M
(SLED)
U1
19
18
17
20
11
13
15
21
V1
W1
COM
U
V
W
VG
+
+
+
PREDRIVER
34
32
38
36
26
24
FOCUS/TRACKING COIL DRIVER
SLED MOTOR DRIVER
IC403 (1/2)
FO2
RO2
FO1
CONTROLLER,
RO1
H BRIDGE DRIVER
FO4
RO4
SPINDLE MOTOR DRIVER
IC404
CONTROL
CIRCUIT
RI2
RI1
RF AMP,
DIGITAL SIGNAL PROCESSOR,
DIGITAL SERVO PROCESSOR,
D-RAM CONTROLLER
IC601
A
92
B
91
RFDC
88
RFAC
81
E
89
F
90
FI2
17
18
FI1
40
41
FI4
21
FI4
22
SYNC
1
CPU
INTERFACE
XRST
6
PWM
APWM
XBRAK
DATA
CLK
XLTCH
24
23
2
FG
3
7
9
8
BUFFER
IC405
100
99
96
95
98
97
104
103
102
72
74
77
78
SFDR
SRDR
FFDR
FRDR
TFDR
TRDR
C176
MDP
MDS
FG/FGSEL
XDRVLT
HG XSTB
HG GUP
S801
HOLD
HOLD
OFF
SCOR
27
40
SCOR
HOLD
VCPU B+
WDCK
WFCK
MDS
XTAO
XTAI
RFAC
MDP
XSOE
SENS
R4M
XLAT
CLOK
SCOR
SDTO
RFDC
SFDR
SRDR
FFDR
FRDR
TFDR
TRDR
SL806
(OPEN)
E
F
B
A
SIGNAL
PROCESSOR
BLOCK
SDTD
SENS
CLOK
161415181711
MSDTI
MSDTO
CLOSE
28
XLAT
MSCK
S804
OPEN
D-RAM
IC602
DOUT
AOUTL,
AOUTR
HPL,
HPR
LRMU
XRST
SYNC
D
E
F
G
H
J
(Page 11)
(Page 11)
(Page 11)
(Page 11)
(Page 11)
(Page 12)
SYSM
25
13
AMUTE
DOUT
D0-D3
A0-A10
XRAS
XWE
XCAS
XTAI
XTAO
AOUT1
AOUT2
HPL
HPR
LRMU
XRST
62
4, 3, 6, 5
116 – 113, 17 – 15, 13 – 11, 117
1
2
9
47
48
51
56
43
44
61
28
2, 3, 24, 25
9 – 12, 15 – 19, 21, 8
5
XRAS
4
XWE
23
XCAS
X601
16.9344MHz
D1 – D4A0 – A10
DIGITAL
OUT
MEMORY
CONTROLLER,
BUS BOOST
BLOCK
LPF
SERVO
BLOCK
R4M
XSOE
WDCK
242232232021
26
2
12
XIN
XLAT
XSOE
GRSCOR
SYSTEM CONTROLLER
VCPU B+
FOK
FOK
65
9
FOK
IC801 (1/3)
SCK
SDTO
K
L
(Page 12)
(Page 12)
1010
5-2.BLOCK DIAGRAM – MAIN Section (2/2) –
D-EJ855
(Page 10)
(Page 10)
(Page 10)
(Page 10)
(Page 10)
VCC3
DOUT
D
AOUTL
HPL
HPR
AOUTR
MUTING
Q303
LINE MUTING
CONTROL SWITCH
Q302
13
12
17
18
15
MUTE_SW
PW_SW
HEADPHONE AMP
IN_L
IN_R
BEEP
IC301
MUTE SW
PW SW
BEEP
OUT_L
OUT_R
BEEPO_L
BEEPO_R
4
9
3
10
S805-809
E
F
LRMU
G
XRST
H
B+ SWITCH
Q301
VCPU B+
OPTICAL
TRANSCEIVER
(LINE OUT JACK)
J302
i
VCPU 2V
4
3
TSB
2
RMKEY
GND
1
J301
LINE OUT
(OPTICAL)
SL807
(TEST)
62479 302625
P21
SYSTEM CONTROLLER
IC801(2/3)
AD SEL
XRST
BEEP
S802
AVLS
LIMIT
NORM
39
AVLS
VCPU B+
S803
G•PROTECTION
2
1
AD KEY
ESP
38
31
TSB
AD RMKEY
VCPU B+
• SIGNAL PATH
: CD PLAY (ANALOG OUT)
: CD PLAY (OPTICAL OUT)
1111
D-EJ855
5-3.BLOCK DIAGRAM – POWER SUPPLY Section –
(Page 10)
(Page 10)
(Page 10)
(Page 10)
(Page 10)
(Page 10)
VG
C
PD
A
SYNC
J
SDTO
L
SCK
K
LD
B
SYSTEM CONTROLLER
IC801 (3/3)
AD CHGMNT
XPOWLT
XWAKE
RESET
LEDDISP
PPG
AGCPWN
POWER CONTROL
IC403 (2/2)
PAPC
3
SYNC
11
DATA
14
CLOCK
13
VLGO4
69
INM4
6
RF4
5
RF41
2
75
66
8
80
29
70
NC
10
21
D801
CHARGE
VCC1
VCPU B+
VCC2
B+ SWITCH
Q418
SWITCHING
Q419
SWITCHING
Q420
VCC3
15
12
16
51
56
61
50
57
75
74
73
78
7
53
79
1
49
58
LATCH
WAKE
RSTB
VCC1
INP2
VLGO2
VCPU
STNG
VCC3
VCC2
VLGO3
RF3
APCREF
DTC2
DTC3
VREF
VDRAM
CHGMNT
VREF
CHGSW
RF1
INM1
RS1
VIN
RF41
RF4
INM4
APCREF
PAPC
DTC2
DTC3
INP2
VCC1
VCC2
VCC3
VCPU
WAKE
LATCH
DATA
CLOCK
LINEAR
CONSTANT CURRENT,
CONSTANT VOLTAGE
CHARGING BATTERY
CHARGE CIRCUIT
SWITCHING
POWER
CIRCUIT
SWITCHING
POWER
CIRCUIT
LINEAR
REGULATOR
INTERFACE
CLK
OR OSC
SAW
GEN.
CHARGING BATTERY
VOLTAGE DETECTOR
CIRCUIT
PRE-DRIVER
VG
POWER
CIRCUIT
VLGO4
VLGO2
VLG3
VG
L5
BATM1
BATM2
CHGMNT
DC IN
BATM1
BATM2
RF1
INM1
DCIN
RS1
CHGSW
VIN
Q421, 422
VIN B+
CHARGE
CHARGE ON
SWITCH
Q412
B+ SWITCH
Q416, 417
RECHARGEABLE
BATTERY
NC-6WM
2PCS. 2.4V
J401
EXT BATT
DC IN 4.5V
+
–
VG
9
L5
8
60
59
46
45
48
43
42
65
CHARGE
CONTROL
Q406, 415
B+ SWITCH
IC402
CHARGE ON
SWITCH
Q403
D405
RIPPLE
FILTER
Q408
D403
B+ SWITCH
AD DCINMNT
EXTBATT
AD BATMNT
CHGGND ON
BATVCC ON
27
33
22
76
7
EXTERNAL BATTERY
DETECT
Q407
1212
D-EJ855
400 to 600
mVp-p
2.0 Vp-p
950 ns
5-4.NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS
Note on Printed Wiring Board
• X : parts extracted from the component side.
• Y : parts extracted from the conductor side.
z
•
•: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
Caution:
Pattern face side:Parts on the pattern face side seen from
(Conductor Side)the pattern face are indicated.
Parts face side:Parts on the parts face side seen from
(Component Side) the parts face are indicated.
• MAIN board is multi-layer printed board. Howe ver , the patterns
: Through hole.
of intermediate-layer have not been included in the diagram.
Note on Schematic Diagram:
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in Ω and 1/
specified.
•%: indicates tolerance.
• C : panel designation.
Note:
The components identified by mark 0 or dotted
line with mark 0 are critical for safety.
Replace only with part
number specified.
• A : B+ Line.
• Power v oltage is dc 4.5 V and fed with regulated dc power
supply from DC IN jack (J401).
• Voltages and w av ef orms are dc with respect to ground in
no-signal conditions.
no mark : CD PLAY
• V oltages are taken with a V OM (Input impedance 10 MΩ).
Voltage variations may be noted due to normal production tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal production tolerances.
• Circled numbers refer to waveforms.
• Signal path.
J: CD PLAY (ANALOG OUT)
c : CD PLAY (OPTICAL OUT)
4
Note:
Les composants identifiés par
une marque 0 sont critiques
pour la sécurité.
Ne les remplacer que par une
pièce portant le numéro
spécifié.