Samsung SCM-7270 User manual

MUSIC CENTER
SCM-7270
SERVICEManual
MUSIC CENTER CONTENTS
1. Precautions
2. Specifications
3. Disassembly and Reassembly
4. Alignment and Adjustments
5. Special Circuit Descriptions
6. Troubleshooting
7. Exploded Views and Parts List
8. Electrical Parts List
9. Block Diagrams
10. PCB Diagrams
11. Wiring Diagram
12. Schematic Diagrams
MONO/ST
CLOCK
TIMER
TUNING
TUNER TAPE CD PHONO
VOLUME
BAND
PRESET/MANUAL
MEMORY CLASSIC POPS ROCK
EQ PRESET
PLAY/PAUSE
STOP/CLEAR
HI-SPEED DUBBING
OPEN/CLOSE
DISPLAY
INTRO
SKIP
SEARCH
REPEAT
RANDOM
ON/STANORY
POWER
DECK 1 REC/PLAY PLAYBACK DECK 2
HIGH SPEED DUBBING CONTINUOUS PLAY
PHONES
REC PLAY REW STOP/EJ PAUSEF.FWD PLAY REW F.FWD STOP/EJ PAUSE
© Samsung Electronics Co.,Ltd. July 1997 Code no. AH68-20169A

1. Precautions
Follow these safety, servicing and ESD precautions to prevent damage and protect against potential hazards
such as electrical shock and X-rays.
Samsung Electronics 1-1
1-1 Safety Precautions
1. Be sure that all of the built-in protective
devices are replaced.
2. When reinstalling the chassis and its
assemblies, be sure to restore all protective
devices, including control knobs and
compartment covers.
3. Make sure that there are no cabinet
openings through which people--
particularly children--might insert fingers
and contact dangerous voltages. Such
openings include the spacing between the
picture tube and the cabinet mask,
excessively wide cabinet ventilation slots,
and improperly fitted back covers.
4. Design Alteration Warning:
Never alter or add to the mechanical or
electrical design of the unit. Example: Do
not add auxiliary audio or video connec-
tors. Such alterations might create a safety
hazard. Also, any design changes or addi-
tions will void the manufacturer's warran-
ty.
5. Leakage Current Hot Check (Figure 1-1):
Warning: Do not use an isolation
transformer during this test. Use a leakage-
current tester or a metering system that
complies with American National Standards
Institute (ANSI C101.1, Leakage Current for
Appliances), and Underwriters Laboratories
(UL Publication UL1410, 59.7).
With the unit completely reassembled, plug
the AC line cord directly into a 120V AC
outlet. With the unit's AC switch first in
the ON position and then OFF, measure the
current between a known earth ground
(metal water pipe, etc.) and all exposed
metal parts. Examples: Handle brackets,
metal cabinets, screwheads and control
shafts. The current measured should not
exceed 0.5 milliamp. Reverse the power-
plug prongs in the AC outlet and repeat.
6. Insulation Resistance Cold Check:
(1) With the unit's AC plug disconnected
from the AC source, connect an electrical
jumper across the two AC prongs. (2) Set
the power switch to ON. (3) Measure the
resistance between the shorted AC plug and
any exposed metallic parts. Example:
Screwheads, antenna, control shafts or
handle brackets.
If any of the exposed metallic parts has a
return path to the chassis, the measured
resistance should be between 1 and 5.2
megohms. If there is no return path, the
measured resistance should be "infinite." If
the resistance is outside these limits, a shock
hazard might exist. See Figure 1-2
Device
Under
Test
(Reading should
not be above
0.5mA)
Leakage
Currant
Tester
Earth
Ground
Test all
exposed metal
surfaces
Also test with
plug reversed
(using AC adapter
plug as required)
2-Wire Cord
Antenna
Terminal
Exposed
Metal Part
ohm Ohmmeter
Fig. 1-1 AC Leakage Test
Fig. 1-2 Insulation Resistance Test

Samsung Electronics1-2
1-1 Safety Precautions (Continued)
7. Components, parts and wiring that appear
to have overheated or that are otherwise
damaged should be replaced with parts
that meet the original specifications.
Always determine the cause of damage or
overheating, and correct any potential
hazards
8. Observe the original lead dress, especially
near the following areas: Antenna
wiring, sharp edges, and especially the
AC and high voltage power supplies.
Always inspect for pinched, out-of-place,
or frayed wiring. Do not change the
spacing between components and the
printed circuit board. Check the AC
power cord for damage. Make sure that
no wires or components touch thermally
hot parts.
9. Product Safety Notice:
Some electrical and mechanical parts
have special safety-related characteristics
which might not be obvious from visual
inspection. These safety features and the
protection they give might be lost if the
replacement component differs from the
original--even if the replacement is rated
for higher voltage, wattage, etc.
10 Components that are critical for safety are
indicated in the circuit diagram by
shading, or . Use replacement
components that have the same ratings,
especially for flame resistance and
dielectric strength specifications. A
replacement part that does not have the
same safety characteristics as the original
might create shock, fire or other hazards.
1-2 Servicing Precautions
1. Servicing precautions are printed on the
cabinet. Follow them.
2. Always unplug the unit's AC power cord
from the AC power source before
attempting to: (a) Remove or reinstall any
component or assembly, (b) Disconnect an
electrical plug or connector, (c) Connect a
test component in parallel with an
electrolytic capacitor.
3. Some components are raised above the
printed circuit board for safety. An
insulation tube or tape is sometimes used.
The internal wiring may be clamped to
prevent contact with thermally hot
components. Reinstall all such elements to
their original position.
4. After servicing, always check that the
screws, components and wiring have been
correctly reinstalled. Make sure that the
portion around the serviced part has not
been damaged.
5. Check the insulation between the blades of
the AC plug and accessible conductive parts
(examples: metal panels, input terminals
and earphone jacks).
6. Insulation Checking Procedure: Disconnect
the power cord from the AC source and
turn the power switch ON. Connect an
insulation resistance meter (500V) to the
blades of the AC plug.
The insulation resistance between each
blade of the AC plug and accessible
conductive parts (see above) should be
greater than 1 megohm.
7. Never defeat any of the B+ voltage
interlocks. Do not apply AC power to the
unit (or any of its assemblies) unless all
solid-state heat sinks are correctly installed.
8. Always connect a test instrument's ground
lead to the instrument chassis ground
before connecting the positive lead; always
remove the instrument's ground lead last.
Precautions
Warning1: First read the "Safety Precautions" section of this manual. If some unforeseen circumstance creates a conflict
between the servicing and safety precautions, always follow the safety precautions.

Samsung Electronics 1-3
1-3 Precautions for Electrostatically Sensitive Devices (ESDs)
1-4 Special Precautions and Warning Labels for Laser Products
1. Some semiconductor ("solid state") devices
are easily damaged by static electricity.
Such components are called Electrostatically
Sensitive Devices (ESDs). Examples include
integrated circuits and some field-effect
transistors. The following techniques will
reduce the occurrence of component
damage caused by static electricity.
2. Immediately before handling any
semiconductor components or assemblies,
drain the electrostatic charge from your
body by touching a known earth ground.
Alternatively, wear a discharging
wrist-strap device. (Be sure to remove it
prior to applying power--this is an electric
shock precaution.)
3. After removing an ESD-equipped assembly,
place it on a conductive surface such as
aluminum foil to prevent accumulation of
electrostatic charge.
4. Do not use freon-propelled chemicals.
These can generate electrical charges that
damage ESDs.
5. Use only a grounded-tip soldering iron
when soldering or unsoldering ESDs.
6. Use only an anti-static solder removal
device. Many solder removal devices are
not rated as "anti-static" (these can
accumulate sufficient electrical charge to
damage ESDs).
7. Do not remove a replacement ESD from its
protective package until you are ready to
install it. Most replacement ESDs are
packaged with leads that are electrically
shorted together by conductive foam,
aluminum foil or other conductive
materials.
8. Immediately before removing the protective
material from the leads of a replacement
ESD, touch the protective material to the
chassis or circuit assembly into which the
device will be installed.
9. Minimize body motions when handing
unpackaged replacement ESDs. Motions
such as brushing clothes together, or lifting
a foot from a carpeted floor can generate
enough static electricity to damage an ESD.
Precautions
UL : Manufactured for U.S.A. Market.
CSA : Manufactured for Canadian Market.
EU : Manufactured for European Market.
SCAN : Manufactured for Scandinavian
Market.
This Product Complies with
DHHS Rules 21CFR, Sub
chapter J.At date of Manu-
facture
(UL)
(SCAN)
(EU)
CERTIFIED ONLY TO CANADIAN
ELECTRICAL CODE.
CERTIFIE EN VERTU DU CODE
CANADIAN DE LELETRICITE
SEULEMENT
(CSA)
CLASS 1
LASER PRODUCT
(EU)
Fig. 1-3 Warning Labels (Location: Enclosure Block)
Fig. 1-4 Warning Labels (Location: Disc Clamper, Inner Side of Unit Door or Nearby Unit Chassis )
CAUTION : INVISIBLE LASER RADIATION WHEN OPEN
AND INTERLOCKS DEFEATEO AVOIDEXPOSURE TO BEAM
ADVARSEL: USYNLIG LASERSTRÅLING VED ABNING
NÅR SIKKERHEDSAFBRYDERE ER UDE AF FUNKTION
UNDGA UDSAETTELSE FOR STRALING
VARO:AVATTAESSA JA SUOJALUKITUS OHITETTAESSA
OLET ALTTINA NAKYMATTÖMALLE LASERSATEILYLLE ALA
KATSO SATEESEEN!
VARNING:OSYNLIG LASERSTRÅLNING NAR DENNA DEL
AR OPPNAD OCH SPARREN AR URKOPPLAD BETRAKTA
EJSTRÅLEN!

Samsung Electronics1-4
1-4 Special Precautions and Warning Labels for Laser Products (Continued)
1-4-1 Warnings
1. When servicing, do not approach the LASER
exit with the eye too closely. In case it is
necessary to confirm LASER beam emission,
be sure to observe from a distance of more
than 30 cm from the surface of the objective
lens on the optical pick-up block.
2. Do not attempt to handle the objective lens
when the DISC is not on the tray.
1-4-2 Laser Diode Specifications
Material: GaAs+ GaAlAs
Wavelength: 760-800 nm
Emission Duration: Continuous
Laser Output: 0.2 mw (measured at a
1.6 mm distance from the objective lens
surface on the optical pick-up block.)
1-4-3 Handling the Optical Pick-up
1. Static electricity from clothing or the body
may cause electrostatic breakdown of the
laser diode in the Optical Pickup. Follow
this procedure:
2. Place a conductive sheet on the work bench
(i.e., the black sheet used for wrapping
repair parts.) Note: The surface of the work
bench should be covered by a copper
ground plane, which is grounded.
3. The repair technician must wear a wrist
strap which is grounded to the copper sheet.
4. To remove the Optical Pickup block:
Place the set on the conductive sheet, and
momentarily touch the conductive sheet
with both hands. (While working, do not
allow any electrostatic sources--such as
clothes--to touch the unit.)
5. Ground the "Short Terminal" (located on the
PCB, inside the Pickup Assembly) before
replacing the Pickup. This terminal should
be shorted whenever the Pickup Assembly
is lifted or moved.
6. After replacing the Pickup, reopen the Short
Terminal. See diagrams below:
Precautions
THE UNIT
(1) WRIST-STRAP
FOR GROUNDING 1M
1M
CONDUCTIVE SHEET
short
terminal short terminal short
terminal short
terminal
SOH91VI(LDP) SOH91CI(CAR,walkman) SOH94T4N
(CMS-V10,CMS-V30)
SOH-A1
(CMS-V10,CMS-V30)

2. Product Specfications
Samsung Electronics 2-1
General
Amp
Cassette
Tuner
Compact Disc
FM
MW
LW
Power source
Power consumption
Dimensions (mm)
Power output
Total harmonic distortion
Frequency range
Signal to noise ratio
Channel separation
Input sensitivity (PHONO)
Frequency range
Usable sensitivity
Signal to noise ratio
IF rejection ratio
Total harmonic distoration
Separation (Stereo)
Frequency range
Usable sensitivity
Signal to noise ratio
IF rejection ratio
Total harmonic distortion
Frequency range
Usable sensitivity
Signal to noise ratio
Frequency range
WOW FLUTTER
Erasing effect (W/Filter)
Signal to noise ratio
Total harmonic distortion
Frequency response
Signal to noise ratio
Channel separation
Total harmonic distortion
125Hz ~ 8KHz
0.35%
60 dB
40 dB
5%
100Hz ~ 10KHz(±1dB)
85 dB(1kHz 0dB)
75 dB(1kHz 0dB)
0.1%(1kHz 0dB)
87.5 ~ 108MHz
15 dB
55 dB
60 dB
1.5%
25 dB
522 ~ 1611KHz
54 dB
40 dB
30 dB
2%
146 ~ 290KHz
60 dB
35 dB
10W
0.5%
50Hz ~ 17kHz
60 dB
45 dB
400mV
AC 230V 50HZ
62 W
350(W) x 328(H) x 316(D)
* Specifications are subject to change without notice.

Samsung Electronics
Remote Control Exploded View
2-2
EQ PRESET MUTE
MONO/ST
PHONO
POWER
PLAY/PAUSE
VOLUME
TUNING TUNING
INTRO
MEMORY BAND
SLEEP PRESET/MANUAL
CLOCK TIMER
TUNER
SKIP/SEARCH STOP
REPEATDISPLAYPROGRAM
TAPE CD
VOLUME

3. Disassembly and Reassembly
3-1 Turn-Table, Cabinet-Front , Cabinet-Bottom
1. Remove Door-CD (Direction A).
2. Release 6 screws !.
3. Remove Turn-Table (Direction B).
4. Release 2 screws @.
5. Release 2 screws #.
6. Remove Front-Cabinet.
45
33
2
1
1
B
3

A
Figure 3-1
Samsung Electronics 3-1

Figure 3-2
3-2 Samsung Electronics
3-2 Deck-CD, Front-PCB, Cassette-Deck, Door-Cassette
Disassembly and Reassembly
1. Release 2 screws !.
2. Remove Deck-CD AssÕy.
3. Release 4 screws @.
4. Remove Deck-CD.
5. Release 17 screws #.
6. Remove Front-PCB, SUB-PCB.
7. Release 7 screws $.
8. Remove Cassette-Deck.
2
3
3
1
4
A
A

3-3 Cabinet-Bottom and Main-PCB
1. Release 3 screws !.
2. Remove the Main-PCB .
1
Figure 3-3
Samsung Electronics 3-3
Disassembly and Reassembly

Figure 3-4
3-4 CD Pack
3-4 Samsung Electronics
Disassembly and Reassembly
3
5
6
8
9
10
17
18
19
20
14
21
11
12
13
14
17
16
17
16
16
23
2
4
7
15
1. Undo 2 screws (A), and remove the Chuck-Bracket @, the Ferrite-Magnet 5, Chuck Union-Table $and
Chunk-Holder &.
2. Undo 2 screws(B), pull the Tray-M1 1forward to remove.
3. Undo 1 screw(C), and remove the Cam-Spring 8and the Cam #.
4. Undo 1 screw(D), and remove the Gear-Pulley (the Belt-Pulley @, the Gear-A %and the Gear-B ^.
5. Undo 2 screws(E), and remove the Motor-Pulley )and the Dc-Motor 0.
6. Undo 2 screws(F), and remove the Leaf-Switch 9and the Detector-Switch “.
Disconnect the Lead-Connector assÕy 4with soldering iron.
7. Remove the AssÕy PCB 3with soldering iron and remove the PCB-Holder +.
8. Undo 4 screws from the CD-Shaft 7, and remove the CD-Rubber 6and the CD-Deck ‘.

Figure 3-5
Samsung Electronics 3-5
3-5 CD Deck
1. Remove the Shaft !.
2. Lift the P/U @.
Note : Do not to touch the surface of lens.
3. Lift the Center-ring #.
4. Remove the Spring-T/Table $.
5. Remove the Turn-Table (M) %.
6. Remove 2 screws ^and then remove the Spindle-Motor &.
7. Remove the Cover-Gear *by pushing the hook.
8. Remove the Gear (c) (by pushing the hook.
9. Lift the Gear(b) ).
10. Remove the Gear(a) 1.
11. Remove 2 screws 2and the then remove the Feed-Motor 3.
12. Remove the Chassis-Deck (M) 4.
Disassembly and Reassembly
3
4
5
6
12
21
8
9
10
11
13
14
7

4. Alignment and Adjustments
4-1 Tuner
Samsung Electronics 4-1
FM THD Adjustment
Minimum Distortion (Figure 4-1)
SSG FREQ.
Adjustment
point
(IT1)
98 MHz
FM DETECTOR COIL
FM Search Level Adjustment
Adjust ISVR1 so that “TUNED” of LCD
is lighted (Figure 4-2)
Figure 4-2 FM Auto Search Level Adjustment
Figure 4-3 FM Stereo Separation Adjustment
Figure 4-1 IF CENTER and THD Adjustment
SSG FREQ.
Adjustment
point
(ISVR1)
98 MHz
SEMI-VR(50KΩ)
FM Seperation Adjustment
L-CH/R-CH : Maximum (Figure 4-3)
SSG FREQ.
Adjustment
point
(ISVR2)
98 MHz
SEMI-VR(5KΩ)
FM SSG GND
30 dB
FM SSG
Output
GND
Speaker
Terminal
FM
Antenna
Terminal
Distortion Meter
Input
SET
Input
output
Oscilloscope
Oscilloscope
Speaker
terminal
FM antenna
OUT
GND VTVM
SET
EXT
FM
SSG
Stereo
Modulator
(Pilot 10%)
75Ω
50Ω
Dummy
Dummy
FM IN
FM Antenna
SET
50 KΩ
5 KΩ
CSVR801
CCON801
ISVR2
ISVR1
IT2
OT1 OT2
OCT2 OCT4
OCT3
OL2
OL1
TCON1
OCT1
IT1
KT431

1. AM Standard Signal Generator (S. S. G) : 400Hz, 30% MOD
2. Oscilloscope
3. VTVM
4. Frequency counter
5. Loop antenna
6. Dummy load (4½)
7. DC voltmeter
1. Check the source voltage.
2. Set function and band switches to the band to be aligned.
3. Set the equalizer, volume and balance controls to mid position
4-2 Samsung Electronics
4-1-1 Test Equipment
4-1-2 Pre-Adjustment
Alignment and Adjustments
Intermediate
frequency(IF)
adjustment
1
2
3
4
5
Figure 4-5
Figure 4-5
522 KHz IT2
OT1 0.9V
9VOCT2
OCT1
OL1
1611 KHz
594 KHz
1404 KHz
Maximum output
Maximum output
Maximum output
Remark
Adjsut.
Point
FREQ.Setting
SSG.FREQ.
Item
Step Pre-Setup
Condition
Figure 4-4
Connect DC
voltmeter to TCON1
and GND(TP1)
AM tracking
adjustment
522 KHz
-
-
-
522 KHz
594 KHz
1404 KHz
AM Signal
Generator Test Loop
Antenna
Speaker
terminal
VTVM
AM
Loop Antenna
Jack
SET TP2
TP1
Input
DC Voltmeter
SET
60 cm GND
Oscilloscope
IN OUT
AM frequency
coverage
adjustment
Repeat step 2 and 3 serveral times
Repeat step 5 and 6 serveral times
Figure 4-4 AM Frequency Coverage Adjustment
Figure 4-5 AM Tracking Adjustment

Samsung Electronics 4-3
Alignment and Adjustments
4-2 Cassette Deck
4-2-1 Additional Test Equipment : Testing Tape
4-2-2 Recording Bias Adjustment
Tape speed
(normal
speed)
adjustment
Figure 4-6 CSVR801 3 KHz
Figure 4-7
To Adjust Remarks
Pre-Setup
Item Pre-Setup
Condition
Figure 4-8
Insert MTT-111 to
Deck A or B
Press PLAY button
Maximum
output and identical
phase of L,R
channel.
Set the screw
after adjustment
Insert MTT-114 to
Deck A and Deck B
Press PLAY button
AZIMUTH
(DECK A,B)
adjustment
IN
Speaker
Terminal
SET
Frequency Counter
Figure 4-6
Figure 4-7
Recording /Play head
REVERSE PLAY
AZIMUTH control knob
Figure 4-8
In Out
Speaker
Terminal Oscilloscope
SET
(GND)
VTVM
V H
CSVR801
CCON801
ISVR2
ISVR1
IT2
OT1 OT2
OCT2 OCT4
OCT3
OL2
OL1
TCON1
OCT1
IT1
KT431
1. Connect frequency counter KC434 and press the REC button.
2. Adjust KT431(BIAS OSC COIL) until frequency counter reads 85 ±0.2KHz.
1. MTT-111(or equivalent) : Test tape on which 3 KHz signal is recorded.(Tape speed adjustment)
2. MTT-114(or equivalent) : Test tape on which 10 KHz signal is recorded. (Azimuth adjustment)

4-3 CD
Alignment and Adjustments
4-4 Samsung Electronics
4-3-1 To Adjust FOCUS BIAS (STOP mode)
1. Set Volt/Div of the oscilloscope to DC 100mV.
2. Ground the scope input and set the waveform to 0V, DC range.
3. Connect the GND terminal of the oscilloscope to Vref,
and (+) terminal to center of TP1.
4. Set NVR1701 to 0mV.
4-3-2 To Adjust Tracking Gain (PLAY mode)
1. Connect the ground terminal of the oscilloscope to Vref and (+) terminal to TP2.
2. Load and play the disc.
3. While the disc is running, adjust the gain with NVR1704 as shown below.
4-3-3 To Adjust Focus Gain (PLAY mode)
1. Connect the ground terminal of the oscilloscope to Vref and (+) terminal to TP1.
2. Load and play the disc.
3. While the disc is running adjust the gain with NVR1703 as shown in the following figure.
4-3-4 To Adjust E/F Balance (PLAY mode)
1. Set Time/Div of the oscilloscope to 2mS.
2. Set Volt/Div of the oscilloscope to 0.5V.
3. Ground the scope input and set to DC, and then
set the DC range.
4. Connect the ground terminal of the oscilloscope to Vref
and (+)terminal to center to TP2.
5. Load and play the disc.
6. Turn NVR1704 counterclockwise to the minimum value.
7. Raise NVR1702 and adjust the waveform so that its middle
comes to ground of the oscilloscope, (or until the upper half
of waveform becomes symmetrical to the bottom half,A=B).
8. Adjust NVR1704(arrow) for normal sound.
TP2
TP1
Vref
NVR1704 NVR1703 NVR1702 NVR1701
TE CENTER FE CENTER
E.F BAL F.BIAS
0V
Normal Frequency
VOLT/DIV : 0.2V
TIME/DIV : 2mS
VOLT/DIV : 0.2V
TIME/DIV : 2mS VOLT/DIV : 0.2V TIME/DIV : 2mS
Low Frequency High Frequency
A=B
0V 0V 0V
Normal Frequency
VOLT/DIV : 0.1V
TIME/DIV : 2mS
VOLT/DIV : 0.1V
TIME/DIV : 2mS VOLT/DIV : 0.1V TIME/DIV : 2mS
Low Frequency High Frequency
0V
100mV
0V
250mV
0V
100mV

6. Troubleshooting
6-1 Amplifier
6-1-1 Power Malfunction
Yes
No
Yes
No
Yes
No
No
Yes
LCD lamp is ON
Pins 73,31 of
UIC1(LC72362)
is at 5V
Voltages at
RQ702,RQ703
are normal
Power Transistor &
fuse normal
Connection
are soldering
of SCON1-FCW2
are normal
Voltages at RQ1, RQ2 and
RFR1 are normal
Voltage at
RQ701 is normal Replace RQ701 Check Voltage at RIC1
Samsung Electronics 6-1

6-1-2 No Output
6-1-3 AM No Sound
Yes
No
Yes
No
No
Voltages at
IIC1(LC1851N) and semi
conductors tuner section
are normal
TCON1 is at
1.5V±1.5 on low coverage
7.5V±0.5 on high
coverage
Voltage at FET
are normal
Voltage at power supply
section
Check pump charge circuitry(OQ5)
connection or soldering of SCON1,
FCW2, FCON1 soldering of pin77
of LC72362
Replace FET
Yes
No
No Check pump charge circuitry
(OQ5) connection of SCON1,
FCW2, FCON1 soldering of pin77
of LC72362N
Yes
Voltage
at LC1851N(IIC1) and tuner
semi conductors are normal
(Refer to Schematic Diagram)
Voltage between
TCON1: AM(MW)
Low coverage 0.9V ±0.5
High coverage 9V ±0.5
LW Low coverage 0.7 V ±0.5
High coverage 4.5V ±0.5
Check loop antenna soldering and
connection of OL1, OL2, OT1,OT2, IT2
Check voltage at power
supply section
6-2 Samsung Electronics
Troubleshooting

6-1-4 Tape Not Playing
6-1-5 Audio Output Problem
Yes
No
Yes No
Yes
No
Connection and soldering of head
wire normal Replace JIC1 (KA22291)
Voltage at
JIC1(KA22291) are normal
(Refer to Schematic
Diagram)
Check power supply circuitry
Noise occurs at
pin3,22 or pin4,21 with volume
control at mid position Noise occurs at pins1,24
Check function selector
section
No
Yes
Yes
Yes
No
Speaker connections are normal
all pins of AIC1(LA4620)
are normal (Refer to Schematic
Diagram)
Voltage at base of AQ601,
AQ651(C945) is less than
0.6V
Pattern & Speaker Jack normal
Check power supply section
Check Muting circuitry
Voltages to
Samsung Electronics 6-3
Troubleshooting

6-2-1 Malfunction of Disc Revolution
Check CLOSE S/W voltage.
CLOSE condition : 0V
Is Focus Search done properly ? Check oscillation of NXF100
(16.9344MHz).
Does Laser function during
Focus Search ? Replace PICK-UP.
Check NIC9282 pin73 voltage Replace NIC9282.
Yes
POWER ON
Check CLOSE MOTOR driving
Replace NIC9220 or NIC9258.
element and CLOSE S/W.
during Focus Search : 5V
Yes
Yes
No
No
No
No
Yes
Yes
6-4 Samsung Electronics
Troubleshooting
6-2 CD