· The included AC power supply cord is for use with this unit
only. Do not use it with other equipment.
3
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SC-EN25P / SC-EN26P / SC- EN27PC
3 Safety Precaution
(This “Safety Precaution” is applied only in U.S.A.)
1. Before servicing, unplug the power cord to prevent an electric shock.
2. When replacing parts, use only manufacturer’s recommended components for safety.
3. Check the condition of the power cord. Replace if wear or damage is evident.
4. After servicing, be sure to restore the lead dress, insulation barriers, insulation papers, shields, etc.
5. Before returning the serviced equipment to the customer, be sure to make the following insulation resistance test to prevent the
customer from being exposed to a shock hazard.
Insulation Resistance Test
1. Unplug the power cord and short the two prongs of the plug with a jumper wire.
2. Turn on the power switch.
3. Measure the resistance value with ohmmeter between the jumper AC plug and each exposed metal cabinet part, such as screw
heads, control shafts, handle brackets, etc. Equipment with antenna terminals should read between 3MΩ and 5.2MΩ to
allexposedparts. (Fig.A) Equipment without antenn a terminals should read approximately infinity to all exposed parts. (Fig.B)
*Note: Some exposed partsmay beisolated from the chassis by design. These will read infinity.
(Fig.A)
(Fig.B)
4. If the measurement is outside the specified limits, there is a possibility of a shock hazard. The equipment should be repaired
and rechecked before it is returned to the customer.
4
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SC-EN25P / SC-EN26P / SC- EN27PC
4 Protection Circuitry
The protection circuitry may have operated if either of the following conditions are noticed:
·No sound is heard when the power is turned on.
·Stop during a performance.
The function of this circuitry is to prevent circuitry damage if, for example, the positive and negative speaker connection wires
are “shorted”, or if speaker with an impedance less than the indicated rated impedance of the amplifier are used.
If this occurs, follow the procedure outline below:
1. Turn off the power.
2. Determine the cause of the problem and correct it.
3. Turn on the power once again after one minute.
Note:
When the protection circuitry functions, the unit will not operate unless the power is first turned off and then on again.
5 Handling Precautions For Traverse Deck (Optical
Pickup)
The laser diode in the traverse deck (optical pickup) may break down due to potential caused by static electricity of clothes or
human body. So, be careful of electrostatic breakdown during repair of the traverse deck (optical pickup).
·Handling of traverse deck (optical pickup)
1. Do not subject the traverse deck (optical pickup) to static electricity as it is extremely sensitive to electrical shock.
2. To prevent the breakdown of the laser diode, an antistatic shorting pin is inserted into flexible board (FFC board).(Fig.1)
3. Take care not to apply excessive stress to the flexible board (FFC board). When removing or connecting the short pin, finish
the job in as short time as possible.
4. Do not turn the variable resistor (laser power adjustment). It has already been adjusted.
·Grounding for electrostatic breakdown prevention
1. Human body grounding (Fig.2)
Use the anti-static wrist strap to discharge the static electricity from your body.
2. Work table grounding (Fig.2)
Put a conduc tive material (sheet) or steel sheet on the area where the traverse deck (optical pickup) is place, and ground
the sheet.
Caution:
The static electricity of your clothes will not be grounded through the wrist strap. So, take care not to let your clothes touch
the traverse deck (optical pickup).
Caution when replacing the Traverse Deck
The traverse deck has a short point shorted with solder to protect the laser diode against electrostatics breakdown. Be sure
to remove the solder from the short point before making connections.
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SC-EN25P / SC-EN26P / SC- EN27PC
(Fig.1)
(Fig.2)
6 Precaution of Laser Diode
Caution:
This unit utilizes a class 1 laser. Invisible laser radiation is emitted from the optical pickup lens. When the unit is turned on:
1. Do not look directly into the pickup lens.
2. Do not use optical instruments to look at the pickup lens.
3. Do not adjust the preset variable resister on the pickup lens.
4. Do not disassemble the optical pickup unit.
5. If the optical pickup is replaced, use the manufacturer’s specified replacement pickup only.
6. Use of control or adjustments or performance of procedures other than those specified herein may result in hazardous radiation
exposure.
CAUTION!
THIS PRODUCT UTILIZES A LASER.
USE OF CONTROLS OR ADJUSTMENTS OR PERFORMANCE OF PROCEDURES OTHER THAN THOSE SPECIFIED HEREIN MAY RESULT
IN HAZARDOUS RADIATION EXPOSURE.
6
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SC-EN25P / SC-EN26P / SC- EN27PC
7 Prevention of Electro Static Discharge (ESD) To
Electrostatically (ES) Devices
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES Devices are integrated circuits and some field-effect transistors
and semiconductor “chip” components. The following techniques should be used to help reduce the incidence of component
damage caused by electro static discharge (ESD).
1. Immediately before handlin g any semiconductor component or semiconductor-equipped assembly, drain off any ESD on your
body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESD wrist strap,
Which should be removed for potential shock resons prior to applying power to the unit under test.
2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as alminum
foil, to prevent electrostatic charge buildup or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.
4. Use only an anti-static solder removal devices. Some solder removal devices not classified as “anti-static (ESD protected)” can
generate electrical charge sufficient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate electrical charges sufficie nt to damage ES devices.
6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most
replacement ES devices are packaged with leads electrically shorted together by conductive foam, alminum foil or comparable
conductive material).
7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material
to the chassis or circuit assembly into which the device will be installed.
Caution
Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged replacement ES devices.(Otherwise harmless motion such as the brushing
together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity (ESD) sufficient to
damage an ES device).
8 Handling the Lead-free Solder
8.1. About lead free solder (PbF)
Distinction of PbF P.C.B.:
P.C.B.s (manufactured) using lead free solder will have a PbF stamp on the P.C.B.
Caution
· Pb free solder has a higher melting point than standard solder; Typically the melting point is 50-70°F (30 - 40°C)
higher.Please use a high temperature soldering iron. In case of the soldering iron with temperature control, please set it to
700± 20 °F (370 ± 10°C).
·Pb free solder will tent to splash when heated too high (about 1100°F/600°C).
·W hen soldering or unsoldering, please completely remove all of the solder on the pins and solder area, and be sure to heat
the soldering points with the Pb free solder until it melts enough.
7
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SC-EN25P / SC-EN26P / SC- EN27PC
9 Operation Checks and Component Replacement
· This section desceibes procedures for checking the
operation of the major printed circuit boards and replacing
the main components.
· For reassembly after operation checks or replacement,
reverse the respective procedures. Specia l reassembly
procedures are described only when required.
9.1. Main Unit
9.1.1. Checking for the main P.C.B., CD
servo P.C.B. and loading motor
P.C.B.
8
Page 9
SC-EN25P / SC-EN26P / SC- EN27PC
· Check the main P.C.B., CD servo P.C.B. and loading motor
P.C.B. as shown below.
9.1.2. Replacement for the traverse deck
ass’y
· Follow the (Step1) - (Step9) of item 9.1.1.
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SC-EN25P / SC-EN26P / SC- EN27PC
9.1.3. Replacement for the CD loading
motor and optical pick-up
·Follow the (Step1) - (Step9) of item 9.1.1.
·Follow the (Step1) - (Step5) of item 9.1.2.
10
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SC-EN25P / SC-EN26P / SC- EN27PC
11
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SC-EN25P / SC-EN26P / SC- EN27PC
9.1.4. Replacement for the CD lid ass’y
and gear CH R
·Follow the (Step1) - (Step11) of item 9.1.1.
·Follow the (Step1) - (Step5) of item 9.1.2.
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SC-EN25P / SC-EN26P / SC- EN27PC
9.1.5. Replacement for the loading motor
·Follow the (Step1) - (Step11) of item 9.1.1.
·Follow the (Step1) - (Step5) of item 9.1.2.
·Follow the (Step1) - (Step6) of item 9.1.4.
9.1.6. Replacement for the pulley gear,
2nd gear, drive gear L, timing gear
and lid kicker
·Follow the (Step1) - (Step11) of item 9.1.1.
·Follow the (Step1) - (Step5) of item 9.1.2.
·Follow the (Step1) - (Step6) of item 9.1.4.
13
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SC-EN25P / SC-EN26P / SC- EN27PC
14
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SC-EN25P / SC-EN26P / SC- EN27PC
9.2. Speaker
9.2.1. Removal of the speaker
9.2.2. Removal of the net frame ass’y
and net protector (SB-EN25)
· Follow the (Step1), (Step2) of item 9.2.1.
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SC-EN25P / SC-EN26P / SC- EN27PC
16
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10 Self Diagnostic Function
10.1. Setting of self diagnostic Function
10.1.1. Setting of self diagnostic mode
1. To enter into self-diagnostic mode:
· Press & hold + key,followed by VOL+ key for more than 2 second s.
2. LCD will show the following display as below:
(LCD Display)
3. Error during Test:
· Press & hold
displayed.
Example:
key (> 2sec) will show blinking error code. If abnormality occurs during test, error code will be
SC-EN25P / SC-EN26P / SC- EN27PC
NOTE: Refer to error code table 11.1.
10.1.2. Test Mode Checking
1. Operation keys and all segment display check mode:
·Activate the Self Diagnosis mode before performing the following steps
·Press & hold REMORT CONTROL 2
·W hen the keys of the main set is pressed, the various corresponding key functions shall light up and display that particular
function. After all the main set keys were pressed, the LCD shows the following (Including CD LED):
2. CD lid OPEN/CLOSE aging test mode:
·Press & hold
·This mode counts the number of times the CD lid open/close (MAX is 65535).
−
− <OPEN>:
− −
key (>5 sec) will enter this mode.
key (>2 sec) will enter this mode.
−
− <CLOSE>:
− −
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SC-EN25P / SC-EN26P / SC- EN27PC
3. CD unit (250Z) and CD lid reliability test mode (Combination )
·Press & hold REMOTE CONTROL
·This test is the combination of CD lid operation and the inner and outer disc access operation aging test.Th e testing process
is as follow: CD lid OPEN→Wait for 1sec. open state→CD lid CLOSE→TOC read → Play all tracks → Increment counter
(Repeat the whole process).
→1→0key (>2 sec) will enter into this test mode.
10.1.3. Exiting from self-diagnostic mode
1. Press the POWER ON/OFF button eihter on the remote controller or main set to exit from Self-Diagnostic mode.
2. The content of abnormalities (error code) are kept as long as the microcontroller memory is backup.
3. If there is an error detected in RAM check at Reset, the content in the RAM shall be initialised and all the contents of
abnormalities shall be cleared.
4. For force clearance, press “STOP” key while in self diagnostic mode.
“CLEAR” is displayed in upper row of LCD for one second followe d by “T” is.
11 Description of Error Code
11.1. Error detection for CD Mechanism block
No.ErrorError Display Problem condition
1CD Open Switch ErrorH15Detect error during opening operation and memorised it as an error.
2CD Close Switch (Bottom Sw)
Error
3CD Rest Switch ErrorF15Under normal operation (Self-Diagnostic Mode inclusive), this error occurs
4Communication between CD
LSI and Micro-P
5Power Supply ErrorF76This error occurs when PDET (Input for detecting over/under voltage of
H16Detect error during closing operation and memorised it as an error.
when the Rest_SW ON is not detected within the specified time (10 s) and
shall be memrised.
F26This error occurs when communication between CD LSI and Micro-P is
abnormal.
power supply) voltage level is not in the range between 1.72V and 2.80V.
18
Page 19
12 Schematic Diagram
12.1. Schematic Diagram Notes
(All schematic diagrams may be modified at any time with the
development of new technology.)
· The voltage value and waveforms are the reference voltage
of this unit measured by DC electronic voltmeter (high
impedance) and oscilloscope on the basis of chassis.
Accordingly, there may arise some error in voltage values
and waveforms depending upon the internal impedance of
the tester or the measuring unit.
SC-EN25P / SC-EN26P / SC- EN27PC
foil.
·Put a conductive mat on the work table.
·Ground the soldering iron.
·Do not touch the pins of IC, LSI or VLSI with fingers
directly.
· Indicated voltage values are the standard values for the unit
measured by the DC electronic circuit tester (highimpedance) with the chassis taken as standard. Therefore,
there may exist some errors in the voltage values,
depending on theinternalimpedanceof the DC circuit tester.
· No mark: All VR is set as a center position.
Important safety notice:
Componentsidentifiedby
markhavespecial
characteristics important for safety.
Furthermore, special parts which have purpose of fireretardant (resistors), high-quality sound (capacitors), lownoise (resistors), etc. are used. When replacing any of
components, be sure to use only manufacture´s specified
parts showninthepa rts list.
Caution!
·IC and LSI are sensitive to static electricity.
·Secondary trouble can be prevented by taking care
during repair.
· Cover the parts boxes made of plastics with
aluminum foil.
·Ground the soldering iron.
·Put a conductive mat on the work table.
·Do not touch the legs of IC or LSI with the fingers
mark havespecial
characteristics important for safety. Furthermore, special
parts which have purposes of fire-retardant (resistors), highquality sound (capacitors), low-noise (resistors), etc. are
used. When replacing any of components, be sure to use
only manufacturer’s specified parts shown in the parts list.
Caution!
IC, LSI and VLSI are sensitive to static electricity.
Secondary trouble can be prevented by taking care during
repair.
· Cover the parts boxes made of plastics with aluminium
19
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SC-EN25P / SC-EN26P / SC- EN27PC
20
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12.2. Schematic Diagram
SCHEMATIC DIAGRAM-1
SC-EN25P / SC-EN26P / SC- EN27PC
NOTE:
The number which noted at the connectors on the schematic diagram
as "SCHEMATICDIAGRAM-1" or "SCHEMATICDIAGRAM-2"indicates
the schematic diagram serial number located on the left corner in the
schematic diagram.
: MAIN SIGNAL LINE
: FM SIGNAL LINE
: FM OSC SIGNAL LINE
: AM OSC SIGNAL LINE
: AM SIGNAL LINE
: FM/AM OSC SIGNAL LINE
() indicates pin No. Right channel.
L2: Print coil
Q608
POWER
SUPPLY
Q609
POWER
SUPPLY
CONT.
IP602
D901~904
D906
F901
T901
POWER
TRANSFORMER
L901
AC IN
AG DATA
AG CLK
MUTE B
CD CLOSE
CD OPEN
PCONT
AC DET
SA-EN25/EN26/EN27(P,PC)BLOCK DIAGRAM
33
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SC-EN25P / SC-EN26P / SC- EN27PC
34
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15 Wiring Connection Diagram
LCD BACK-LIGHT P.C.B.
C
1. . . . . . .
FFC801
. . . . . . . . . . . . . . . . .
LCD P.C.B.
26
JW8011
2
1
D
JW352
2
1
SW P.C.B.
G
2 1
JW352
POWER TRANSFORMER P.C.B.
I
P901
1 . . 4
SC-EN25P / SC-EN26P / SC- EN27PC
SENSOR P.C.B.
E
JW1001
1 . 3
3
.
1
P1001
26. . . . . . .
. . . . . . . . . . . . . . . . .
FP801
1
2 1
P352
MAIN P.C.B.
B
P601
6 . . . . 1
. . . . . . .
16
. . . . . . . .
17
FP701
1 . . 4
JW901
2
1
P351
1 . . . . 6
OPTICAL PICK-UP
CD SERVO P.C.B.
A
CN702
. . . . . . . .
1
2 . . . . . . .
CN701
2
1
.
.
.
.
.
.
.
.
.
.
.
.
16
15
17
16
1 . . . . 6
JW801
OPEARATION P.C.B.
H
35
1 . . . . 6
MOTOR P.C.B.
F
1
.
.
.
.
6
JW351
Page 36
SC-EN25P / SC-EN26P / SC- EN27PC
36
Page 37
16 Measurements and Adjustments
16.1. Tuner Adjustment
16.1.1. Required tools and equipment
·Signal generator
·AM loop antenna
·Oscilloscope or electrical voltage meter
·Headphone jig
16.1.2. Preparations for Adjustment
·Apply under [9. Operation Checks and Component Replacement].
·Connect to the power supply (AC120V).
·Maximize the volume.
16.1.3. AM RF Adjustment
1. Input AM signal generator output from the AM loop antenna.
2. Connect a measuring instrument to the headphone jack.
3. Tune to the signal (SG 603kHz).
4. Adjust L51 so that the output reaches maximum.(Fig.01)
SC-EN25P / SC-EN26P / SC- EN27PC
16.1.4. AM IF Adjustment
1. Follow the steps 1 and 2 of AM RF Adjustment.
2. Tune to the signal (SG 450kHz).
3. Revolve the T1 core and adjust that the output waveforms reaches maximum. (Fig.02)
16.1.5. AM VCO Adjustment
1. Input AM single generator output from the AM loop antenna.
2. Set the electrical voltage meter to TP1 - TP3.
3. Tune to the signal (SG 520kHz).
4. Adjust L51 so that the output reaches DC 1.4±0.3V.
16.1.6. FM RF Adjustment
1. Set the frequency of FM signal generator to 87.9MHz.
2. Input to TP1(RF I/P) - TP2(RF O/P) through FM dummy antenna.
3. Adjust L7 so that the output reaches maximum. (Fig.01)
4. Take measurement at point 1, point 2 and point 3 (GND). Range from 2.15 ± 0.5 V
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SC-EN25P / SC-EN26P / SC- EN27PC
16.2. Adjustment Point
(Fig.01)
(Fig.02)
38
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17 Terminal Functions of ICs
SC-EN25P / SC-EN26P / SC- EN27PC
·IC801 (MN101C74FAD) Microprocessor
Pin No.MarkI/OFunction
1-4COM0 - COM4O LCD common output
5-7VLC3 -VLC1- LCD power supply
8C2- Capacitor terminal for
pressure
9LCD_GNDO/I LCD GND
10PC1IWriting data
11PC2I/O Writing clock
12CD_BOTTOM_SWI/O CD bottom switch
13CD_TOP_SWI/O CD top switch
14MBP1O Beet proof 1
15MBP2O Beet proof 2
16VSS- GND
17OSC1I Main oscillator input (8MHz)
18OSC2O Main oscillator output (8MHz)
19VDD- VDD +3.3V
20XII Sub oscillator input (32kHz)
21XOO Sub oscillator output (32kHz)
22NMODI CD Memory mode select
23NRESETI Reset
24DMODI Silial writing mode
25VREF+- A/D converter reference
voltage
26KEYSWA/D Key input
27REGIONA/D Aria/Model select
28PDETA/D Main voltage check
29CRTA/D CR timer
30NCI N.C.
31CD_OPENO CD open switch function
32CS_CLOSEO CD close switch function
33AG_DATAO ASP data output
34AG_CLKO ASP clock output
35PLL_D0I/O PLL data input
36PLL_D1O/I PLL data output
37PLL_CLKO/I PLL CLK
38PLL_CEO/I PLL chip select output
39MCLKO/I CD LSI command clock
40MDATAO/I CD LSI command data
41STATUSI/O CD status
42MLDO/I CD LSI command load
43REST_SWI/O CD travers limit switch
44CD_RESETO CD reset switch
45MUTE_AI/O Audio Mute Output (L: MUTE
ON)
46NC(EX_BASS)I N.C.
47NCI N.C.
48REM_INI Remocon input
49ACDETI Ac detection
50BLKCKI/O CD subcode block clock input
51PCONTO Power control output
52CD_SET1I CD setting 1
53CD _SET2I CD setting 2
54CD_SET3I CD setting 3
55NC(REC_H)I Not used. Connected with
GND exterminally through
resistance.
56NC(TAPE_L)I N.C.
57E_CSO EEPROM chip select
58E_DATAI/O EEPROM DATA
59E_CLKO EEPROM CLOCK
60NC(TEST1)I TEST 1 terminal
61NC(TEST2)I TEST 2 terminal
62NC(JOG1)I Not used
63NC(JOG2)I Not used
64STBY_LEDO Standby_LED
Pin No.MarkI/OFunction
65NC(AUX_DET)I Not used
66NCI Not used
67NCI Not used
68NCI Not used
69-80NCINot used
81-100SEG19-SEG0O LCD Segment Output
39
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SC-EN25P / SC-EN26P / SC- EN27PC
18 Replacement Parts List
Notes:
· Important safety notice:
Componentsidentifiedby
mark havespecial
characteristics important for safety.
Furthermore, special parts which have purposes of fireretardant (resistors), high-quality sound (capacitors), lownoise (resistors), etc. are used.
When replacing any of these components, be sure to use
only manufacturers’s specified parts shown in the parts list.
· Warning: This product uses a laser diode. Refer to caution
statements on “Precaution of Laser Diode”
· Capacitor values are in microfarad (µF) unless specified
otherwise, P=Pico -farads(pF); Farads.
· Resistance values are in ohms, unless specified otherwise,
1K=1,000(ohms).
· The marking (RTL) indicates the Retention Time is limited
for this item. After the discontinuation of this assembly in
production, it will no longer be available.
·All parts are supplied by ASPC.
·The parenthesized indications in the Remarks column
specify the areas. (Refer to the cover page for area.)
Parts without these indications can be used for all areas.