Page 1
PRODUCT SAFETY SERVICING GUIDELINES
CAUTION : DO NOT ATTEMPT TO MODIFY THIS PRODUCT IN
ANY WAY. NEVER PERFORM CUSTOMIZED INSTALLATIONS
WITHOUT MANUFACTURERS APPROVAL. UNAUTHORIZED
MODIFICATIONS WILL NOT ONLY VOID THE WARRANTY, BUT
MAY LEAD TO YOUR BEING LIABLE FOR ANY RESULTING
PROPERTY DAMAGE OR USER INJURY.
SERVICE WORK SHOULD BE PERFORMED ONLY AFTER YOU
ARE THOROUGHLY FAMILIAR WITH ALL OF THE FOLLOWING
SAFETY CHECKS AND SERVICING GUIDELINES. TO DO
OTHERWISE, INCREASES THE RISK OF POTENTIAL HAZARDS
AND INJURY TO THE USER.
WHILE SERVICING, USE AN ISOLATION TRANSFORMER FOR
PROTECTION FROM AC LINE SHOCK.
SAFETY CHECKS
AFTER THE ORIGINAL SERVICE PROBLEM HAS BEEN
CORRECTED. A CHECK SHOULD BE MADE OF THE
FOLLOWING.
SUBJECT : FIRE & SHOCK HAZARD
1.BE SURE THAT ALL COMPONENTS ARE POSITIONED IN
SUCH A WAY AS TO AVOID POSSIBILITY OF ADJACENT
COMPONENT SHORTS. THIS IS ESPECIALLY IMPORTANT
ON THOSE MODULES WHICH ARE TRANSPORTED TO AND
FROM THE REPAIR SHOP.
2. NEVER RELEASE A REPAIR UNLESS ALL PROTECTIVE
DEVICES SUCH AS INSULATORS, BARRIERS, COVERS,
SHIELDS, STRAIN RELIEFS, POWER SUPPLY CORDS, AND
OTHER HARDWARE HAVE BEEN REINSTALLED PER
ORIGINAL DESIGN. BE SURE THAT THE SAFETY PURPOSE
OF THE POLARIZED LINE PLUG HAS NOT BEEN DEFEATED.
3. SOLDERING MUST BE INSPECTED TO DISCOVER POSSIBLE COLD SOLDER JOINTS, SOLDER SPLASHES OR SHARP
SOLDER POINTS. BE CERTAIN TO REMOVE ALL LOOSE
FOREIGN PARTICLES.
4. CHECK FOR PHYSICAL EVIDENCE OF DAMAGE OR
DETERIORATION TO PARTS AND COMPONENTS. FOR
FRAYED LEADS, DAMAGED INSULATION (INCLUDING AC
CORD). AND REPLACE IF NECESSARY FOLLOW ORIGINAL
LAYOUT, LEAD LENGTH AND DRESS.
5. NO LEAD OR COMPONENT SHOULD TOUCH A RECEIVING TUBE OR A RESISTOR RATED AT 1 WATT OR MORE. LEAD
TENSION AROUND PROTRUDING METAL SURFACES MUST
BE AVOIDED.
6. ALL CRITICAL COMPONENTS SUCH AS FUSES,
FLAMEPROOF RESISTORS, CAPACITORS, ETC. MUST BE
REPLACED WITH EXACT FACTORY TYPES, DO NOT USE
REPLACEMENT COMPONENTS OTHER THAN THOSE
SPECIFIED OR MAKE UNRECOMMENDED CIRCUIT
MODIFICATIONS.
7. AFTER RE-ASSEMBLY OF THE SET ALWAYS PERFORM AN AC LEAKAGE TEST ON ALL EXPOSED METALLIC PARTS OF
THE CABINET, (THE CHANNEL SELECTOR KNOB, ANTENNA
TERMINALS. HANDLE AND SCREWS) TO BE SURE THE SET
IS SAFET TO OPERATE WITHOUT DANGER OF ELECTRICAL
SHOCK. DO NOT USE A LINE ISOLATION TRANSFORMER
DURING THIS TEST USE AN AC VOLTMETER, HAVING 5000
OHMS PER VOLT OR MORE SENSITIVITY, IN THE
FOLLOWING MANNER; CONNECT A 1500 OHM 10 WATT
RESISTOR, PARALLELED BY A .15 MFD, 150V AC TYPE
CAPACITOR BETWEEN A KNOWN GOOD EARTH GROUND
(WATER PIPE, CONDUIT, ETC.) AND THE EXPOSED
METALLIC PARTS, ONE AT A TIME.
MEASURE THE AC VOLTAGE ACROSS THE COMBINATION
OF 1500 OHM RESISTOR AND .15 MFD CAPACITOR.
REVERSE THE AC PLUG AND REPEAT AC VOLTAGE
MEASUREMENTS FOR EACH EXPOSED METALLIC PART. VOLTAGE MEASURE MUST NOT EXCEED 75 VOLTS R.M.S.
THIS CORRESPONDS TO 0.5 MILLIAMP AC ANY VALUE
EXCEEDING THIS LIMIT CONSTITUTES A POTENTIAL
SHOCK HAZARD AND MUST BE CORRECTED IMMEDIATELY.
SUBJECT : GRAPHIC SYMBOLS
SUBJECT : TIPS ON PROPER INSTALLATION
1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS,
CUBBYHOLE OR CLOSELY FITTING SHELF SPACE. OVER
OR CLOSE TO HEAT DUCT, OR IN THE PATH OF HEATED
AIR FLOW.
2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS:
OUTDOOR PATIO INSTALLATIONS WHERE DEW IS A
FACTOR, NEAR STEAM RADIATORS WHERE STEAM
LEAKAGE IS A FACTOR, ETC.
3. AVOID PLACEMENT WHERE DRAPERIES MAY OBSTRUCT REAR VENTING. THE CUSTOMER SHOULD ALSO AVOID THE
USE OF DECORATIVE SCARVES OR OTHER COVERINGS
WHICH MIGHT OBSTRUCT VENTILATION.
4. WALL AND SHELF MOUNTED INSTALLATIONS USING A COMMERCAL MOUNTING KIT MUST FOLLOW THE FACTORY
APPROVED MOUNTING INSTRUCTIONS A PRODUCT
MOUNTED TO A SHELF OR PLATFORM MUST RETAIN ITS
ORIGINAL FEET (OR THE EQUIVALENT THICKNESS IN
SPACERS) TO PROVIDE ADEQUATE AIR FLOW ACROSS
THE BOTTOM, BOLTS OR SCREWS USED FOR FASTENERS
MUST NOT TOUCH ANY PARTS OR WIRING. PERFORM
LEAKAGE TEST ON CUSTOMIZED INSTALLATIONS.
5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A PRODUCT ON SLOPING SHELF OR A TILTED POSITION,
UNLESS THE PRODUCT IS PROPERLY SECURED.
6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE ON ITS MOUNTING TO THE CART. CAUTION THE
CUSTOMER ON THE HAZARDS OF TRYING TO ROLL A CART
WITH SMALL CASTERS ACROSS THRESHOLDS OR DEEP
PILE CARPETS.
7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR STAND WHICH HAS NOT BEEN LISTED BY UNDERWRITERS
LABORATORIES, INC. FOR USE WITH THEIR SPECIFIC
MODEL OF TELEVISION RECEIVER OR GENERICALLY
APPROVED FOR USE WITH T.V.S OF THE SAME OR
LARGER SCREEN SIZE.
8. CAUTION CUSTOMERS AGAINST THE USE OF EXTENSION CORDS, EXPLAIN THAT A FOREST OF EXTENSIONS
SPROUTING FROM A SINGLE OUTLET CAN LEAD TO
DISASTROUS CONSEQUENCES TO HOME AND FAMILY.
THE LIGHTNING FLASH WITH ARROWHEAD SYMBOL, WITHIN AN
EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE USER TO THE
PRESENCE OF UNINSULATED DANGEROUS VOLTAGE WITHIN THE
PRODUCTS ENCLOSURE THAT MAY BE OF SUFFICIENT MAGNITUDE TO
CONSTITUTE A RISK OF ELECTRIC SHOCK.
THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS
INTENDED TO ALERT THE USER TO THE PRESENCE OF IMPORTANT
OPERATING AND MAINTENANCE (SERVICING) INSTRUCTIONS IN THE
LITERATURE ACCOMPANYING THE APPLIANCE.
Page 2
SERVICING PRECAUTIONS
CAUTION : Before servicing the A/V Receiver covered by this
service data and its supplements and addends, read and follow the
SAFETY PRECAUTIONS. NOTE: if unforeseen circumstances
create conflict between the following servicing precautions and any
of the safety precautions in this publication, always follow the safety
precautions.
Remember Safety First:
General Servicing Precautions
1. Always unplug the A/V Receiver AC power cord from the AC power source before:
(1) Removing or reinstalling any component, circuit board,
module, or any other assembly.
(2) Disconnecting or reconnecting any internal electrical plug or
other electrical connection.
(3) Connecting a test substitute in parallel with an electrolytic
capacitor.
Caution : A wrong part substitution or incorrect polarity installation
of electrolytic capacitors may result in an explosion hazard.
2. Do not spray chemicals on or near this A/V Receiver or any of its assemblies.
3. Unless specified otherwise in this service data, clean electrical contacts by applying an appropriate contact cleaning solution to
the contacts with a pipe cleaner, cottontipped swab, or
comparable soft applicator.Unless specified otherwise in this service data, lubrication of
contacts is not required.
4. Do not defeat any plug/socket B+ voltage interlocks with which instruments covered by this service manual might be equipped.
5. Do not apply AC power to this A/V Receiver and/or any of its electrical assemblies unless all solid-state device heat sinks are
correctly installed.
6. Always connect test instrument ground lead to the appropriate ground before connecting the test instrument positive lead. Always
remove the test instrument ground lead last.
Insulation Checking Procedure
Disconnect the attachment plug from the AC outlet and turn the
power on. Connect an insulation resistance meter(500V) to the
blades of the attachment plug. The insulation resistance between
each blade of the attachment plug and accessible conductive parts
(Note 1) should be more than 1M-ohm.
Note 1 : Accessible Conductive Parts including Metal panels, Input
terminals, Earphone jacks, etc.
Electrostatically Sensitive (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 static electricity.
1. Immediately before handling any semiconductor component or
semiconductor-equipped assembly, drain off any electrostatic
charge on your body by touching a known earth ground.
Alternatively, obtain and wear a commercially available
discharging wrist strap device, which should be removed for
potential shock reasons 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 aluminum
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 antistatic solder removal device. Some solder
removal devices not classified a anti-static can generate
electrical charges sufficient to damage ES devices.
5. Do not use freonpropelled chemicals. These can generate
electrical charge sufficient 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, aluminum foil, or
comparable conductive material).
7. lmmediately 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 handing unpackaged replacement ES devices. (Normally 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 sufficient to damage
an ES device.)
Page 6
+15V-15V
+15V
-15V +15V
OMC1
-15V +15V
OMC1
OMC2
OMC3
OMC2 OMC3
+15V -15V
+15V +15V +15V
+15V
-15V
-15V
+15V
2C32
4.7uF 50V
8
910
2U10C
TL074
2R98
24K
2C39
4.7uF 50V
2R84
36K
2D2
1N4148
2C68
0.1uF
2C22 4.7uF 50V
2C494.7uF 50V
2C63
0.1uF
2C33
4.7uF/50V
2Q3
2SC2240
2R102
1K
2
3
1
2D7
BAS70-04
2C23
4.7uF 50V
2D5
1N4148
2R104
10K
2D11
1N4148
1213
14
2U11D TL074
2C59
0.1uF
2R100
9.1K
2R101
30.1K
2R82
20.0K
2R18
2.7M
8
910
2U9C
TL074
2D15
1N4148
56
7
2U2B OPA4134
1213
14
2U9D
TL074
2Q2
2SC2240
2R97
24K
2R87
4.7K
2R8
36K
2R79
20.0K
2R5
100k
1
32
4 11 2U11A
TL074
2R81
100k
1
32
4 11 2U10A
TL074
2C11
4.7uF 50V
2C5 22pF
2D3
1N4148
56
7
2U11B
TL074 56
7
2U9BTL074
2R66
10K
2R27
162K
1
32
4 11 2U2A
OPA4134
2R29
1M
2R65
162K
2R42
1K
2R1
162K
8
910
2U11C
TL074
2C24
22pF
2C52
4.7uF 50V
2C51
4.7uF 50V
2R28
10K
2D16
1N4148 2D4
1N4148
2C1
4.7uF 50V
2C13
4.7uF 50V
2R30
4.75K
2
3
1
2D6
BAS70-04
2R7
22K
2C14
4.7uF 50V
2C64
0.1uF 2R45
22K
2R11
4.7K
2C3 4.7uF 50V
2R113
1M
2D9
1N4148
2D8
1N4148
2R112
10K
1213
14
2U2D OPA4134
2R68
4.75K
2R94
2.7M
2
3
1
2D13
BAS70-04
2C42
4.7uF 50V
2R58
10K
2R26
1K
2D17
1N4148
2
3
1
2D12
BAS70-04
2R4
1K
2R75
1M
2R40
162K
1
32
4 11 2U9A
TL074
2D10
1N4148
2C20
4.7uF 50V
2D19
1N4148
2R46
36K
2C41
4.7uF 50V
2R61
39K
2C4
4.7uF 50V
2
3
1
2D1
BAS70-04
2R21
24K
2R25
30.1K
2R60
24K
2C65
0.1uF
2Q1
2SC2240
8
910
2U2C
OPA4134
2R93
1.00M
2R22
24K
2R20
10K
2R119
24K
2C60
0.1uF
2D20
1N4148
2R64
1K
2R96
10K
2R23
39K 2C30
4.7uF 50V
2R36
10K
2R55
1.00M
2R103
162K
2R80
1K
2C66
0.1uF
2D21
1N4148
2C43 22pF
2R62
9.1K
2R59
24K
2R63
30.1K
2R44
20.0K
2D23
1N4148
2C61
0.1uF
2R37
1M
2R24
9.1K
1213
14
2U10D
TL074
2R83
22K
2R99
39K
2R17
1.00M
2R56
2.7M
2R117
OMIT 2R49
4.7K
2R41
20.0K
2R118
9.1K
2C67
0.1uF
2D14
1N4148
2R74
10K
2R105
1M
2R43
100k
2R2
20.0K
2R106 4.75K
2C62
0.1uF
2
3
1
2D18
BAS70-04
2R78
162K
2R6
20.0K
2R67
1M 56
7
2U10B
TL074
-56V pk max.
7V pk max 56V pk max. 7V pk max
+7.95V @ FAULT
+5.40V @ Fan-On
12345678910 2P4
10PIN
12345678910 2PX2
10PIN
2R127
47K 2R126
47K 2R128
47K
OUTPUT3SOUTPUT2SOUTPUT1S PRE3PRE2PRE1
OUTPUT1S RETURN1 RETURN2 RETURN3 OUTPUT2S OUTPUT3S
2R15
1M 2R53
1M 2R91
1M
RETURN1RETURN2RETURN3
IN1 IN2 IN3
IN1IN2IN3
OMC SENCE
OMC SENCETEMP SENCE
+15V-15V
PRE1 PRE2 PRE3
-15V
56
7
2U1B
TL074
1
32
4 11
2U1A
TL074 8
910
2U1C
TL074
2R132
10K 2R133
10K 2R134
10K
2Q4 2SC1815 2Q5
2SC1815 2Q6
2SC1815
2Q8
2SA1015 2Q9
2SA1015 2Q7
2SA1015
2D29
1N4148 2D28
1N4148 2D27
1N4148
2D24
1N4148 2D25
1N4148 2D26
1N4148 2R120
47K
2R129
10
2R121
47K
2R130
10 2R131
10
2R124
10K 2R123
10K 2R125
10K 2R122
47K
OMC1
OMC2
OMC3
TEMP R
TEMP R
TEMP SENCE
1
2
3414
13
12
11
OPA4134
5
67 10
9
8
OUT A
OUT B OUT D
OUT C
+IN A +IN B
+IN C+IN D
-IN A
-IN B -IN C
-IN D
V+ V-
TEXT
ECB
2SA1015GR
2SC1815GR
2SC2240GR
BAS70-04
TL074
OMC
TM
C 2000 NAD Electronics International, a division of Lenbrook Industries \
Limited
2C2
100P 2C7
100P 2C21
100P
12345678
2PX4
8PIN
PROTECTION
TEMP PRO
AC DET
PROTECTIONTEMP PROAC DET
+15V
-15V -15V
+15V
-15V
+15V
2D22
1N4148
3R3
3K3
3R16
0.1/2W 3R19
0.1/2W
3C10
100P
3C12
100P
3Q5
C2240
3C5
10U/25V
3L1
10uH
D2GND
D2GND
3C7
47P
3R15
3.3/2W
3R5
10
3R18
120
3D4
1N4148
3C4
10U/25V
3R8
14K
3R10
1K 3R4
10
3R11
68
3R20
68
3R6
4K 3R9
200
3C6
220P
3C11
0.1uF
3Q2
A970
3Q4
D669
3Q3
A970
3Q1
B649
3C2
47uF/50V
3R14
200
3C13
0.1uF
+15VA
3R7
220
3R12
68 3R17
33K
3C14
10n
3Q7
A970
3R2 68
3R13100
3C8
220uF/25V Bi-Polar
3R1
1K
amp in1
3C9
47uF/50V
3D3
1N4148 3D2
1N4148 3D1
1N4148
3Q6
SAP15N 3Q8
SAP15P
3C1
0.1uF
3C3
15P
+40V
-40V
3R23
3K3
3R36
0.1/2W 3R39
0.1/2W
3C24
100P 3C26
100P
3Q13
C2240
3C19
10U/25V
3L2
10uH
D2GND
D2GND
3C21
47P
3R35
3.3/2W
3R25
10
3R38
120
3D8
1N4148
3C18
10U/25V
3R28
14K
3R30
1K 3R24
10
3R31
68
3R40
68
3R26
4K 3R29
200
3C20
220P
3C25
0.1uF
3Q10
A970
3Q12
D669
3Q11
A970
3Q9
B649 3C16
47uF/50V
3R34
200
3C27
0.1uF
+15VA
3R27
220
3R32
68 3R37
33K
3C28
10n
3Q15
A970
3R22
68
3R33
100
3C22
220uF/25V Bi-Polar
3R21
1K
amp in2
3C23
47uF/50V
3D7
1N4148 3D6
1N4148 3D5
1N4148
3Q14
SAP15N 3Q16
SAP15P
3C15
0.1uF
3C17
15P
+40V
-40V
3R43
3K3
3R56
0.1/2W 3R59
0.1/2W
3C38
100P 3C40 100P
3Q21
C2240
3C33
10U/25V
3L3
10uH
D2GND
D2GND
3C35
47P
3R55
3.3/2W
3R45
10
3R58
120
3D12
1N4148
3C32
10U/25V
3R48
14K
3R50
1K 3R44
10
3R51
68
3R60
68
3R46
4K 3R49
200
3C34
220P
3C39
0.1uF
3Q18
A970
3Q20
D669
3Q19
A970
3Q17
B649 3C30
47uF/50V
3R54
200
3C41
0.1uF
+15VA
3R47 220
3R52
68 3R57
33K
3C42
10n
3Q23
A970
3R42
68
3R53 100
3C36
220uF/25V Bi-Polar
3R41
1Kamp in3 3C37
47uF/50V
3D11
1N4148 3D10
1N4148 3D9
1N4148
3Q22
SAP15N 3Q24
SAP15P
3C29
0.1uF
3C31
15P
+40V
-40V
1 2
2RT1
100K@25C
12345678910 2PX1
12PIN
amp in1amp in2amp in3 output3output2output1
+15VA
output1 output2 output3
3R62
1K
3R61
15K
3R68
22K
3C43
22N
3Q26
C1815
3D13
1N4148
3R64
1K
3R63
15K
3R69
22K
3C44
22N
3Q27
C1815
3D14
1N4148
3R66
1K
3R65
15K
3R70
22K
3C45
22N 3Q28
C1815 3D15
1N4148
3R74
22K
3C50
330u/16
3C49
0.22u
3R72
15K
3R73
56K
3C47
33u/50V
PROTECTION CIR.
+40V
1 2
34
5
6
7
8IC44
UPC1237HA
3R75
56K 3R76
56K 3R77
56K
3RL1B
12V RELAY 3RL2B
12V RELAY 3RL3B
12V RELAY
3D16
1N4148
+40V 3Q25
2SB647
3R67
6K8
3C46
10u/25V
3RL1A
5A RELAY 3RL2A
5A RELAY 3RL3A
5A RELAY
output1 output2 output3
output1 output2 output3
3R78
3K3 +40V
+15VA
3D17
15V D2GND
12345678
2P3
8PIN
-40V+40V
12345678
2PX3
8PIN
12345 2P2
5PIN
3C52
100uF/50V 3C53
100uF/50V
3C54
100uF/50V 3C55
100uF/50V
3C56
100uF/50V 3C57
100uF/50V
+40V -40V
3C51
4.7uF
3Q29
2SC1815
3C58
47uF/25V
D2GND
B DCS E E S CDB SAP15N
SAP15P
2Q10
2SC1815
2R3
1K
3Q30
2SB647
3R80
10K
3R81
39K
3R82
10K
+40V
