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FILE NO. 810-200434

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1. Precautions
2. Reference Information
3. Product Specification
4. Operating Instructions
5. Disassembly and Reassembly
6. Alignment and Adjustments
7. Circuit Operating Descriptions
8. VCR Deck Operating Descriptions
9. Troubleshooting
10. Exploded View and Parts List
11. Electrical Parts List
12. Block Diagram
13. Wiring Diagram
14. PCB Diagrams
15. Schematic Diagrams

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1. Precautions
1-1 Safety Precautions
1) Before returning an instrument to the customer,
always make a safety check of the entire instrument,
including, but not limited to, the following items:
(1) Be sure that no built-in protective devices are
defective or have been defeated during servicing.
(1)Protective shields are provided to protect both
the technician and the customer. Correctly replace
all missing protective shields, including any
removed for servicing convenience.
(2)When reinstalling the chassis and/or other as-
sembly in the cabinet, be sure to put back in place
all protective devices, including, but not limited to,
nonmetallic control knobs, insulating fish papers,
adjustment and compartment covers/shields, and
isolation resistor/capacitor networks. Do not oper-
ate this instrument or permit it to be operated with-
out all protective devices correctly installed and
(2) Be sure that there are no cabinet openings through
which adults or children might be able to insert
their fingers and contact a hazardous voltage. Such
openings include, but are not limited to, excessive-
ly wide cabinet ventilation slots, and an improper-
ly fitted and/or incorrectly secured cabinet back
(3) Leakage Current Hot Check-With the instrument
completely reassembled, plug the AC line cord
directly into a 120V AC outlet. (Do not use an iso-
lation 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) 1270 (40.7). With
the instrument's AC switch first in the ON position
and then in the OFF position, measure from a
known earth ground (metal water pipe, conduit,
etc.) to all exposed metal parts of the instrument
(antennas, handle brackets, metal cabinets, screw-
heads, metallic overlays, control shafts, etc.), espe-
cially any exposed metal parts that offer an electri-
cal return path to the chassis.
Any current measured must not exceed 0.5mA.
Reverse the instrument power cord plug in the out-
let and repeat the test. See Fig. 1-1.
Any measurements not within the limits specified
herein indicate a potential shock hazard that must
be eliminated before returning the instrument to
the customer.
Fig. 1-1 AC Leakage Test
(4) Insulation Resistance Test Cold Check-(1) Unplug
the power supply cord and connect a jumper wire
between the two prongs of the plug. (2) Turn on the
power switch of the instrument. (3) Measure the
resistance with an ohmmeter between the
jumpered AC plug and all exposed metallic cabinet
parts on the instrument, such as screwheads,
antenna, control shafts, handle brackets, etc. When
an exposed metallic part has a return path to the
chassis, the reading should be between 1 and 5.2
megohm. When there is no return path to the chas-
sis, the reading must be infinite. If the reading is
not within the limits specified, there is the possibil-
ity of a shock hazard, and the instrument must be
repaired and rechecked before it is returned to the
customer. See Fig. 1-2.
Fig. 1-2 Insulation Resistance Test
Metal Part

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2) Read and comply with all caution and safety re-
lated notes on or inside the cabinet, or on the chas-
3) Design Alteration Warning-Do not alter or add to
the mechanical or electrical design of this instru-
ment. Design alterations and additions, including
but not limited to, circuit modifications and the
addition of items such as auxiliary audio output
connections, might alter the safety characteristics of
this instrument and create a hazard to the user. Any
design alterations or additions will make you, the
servicer, responsible for personal injury or property
damage resulting therefrom.
4) Observe original lead dress. Take extra care to
assure correct lead dress in the following areas:
(1) near sharp edges, (2) near thermally hot parts (be
sure that leads and components do not touch ther-
mally hot parts), (3) the AC supply, (4) high voltage,
and (5) antenna wiring. Always inspect in all areas
for pinched, out-of-place, or frayed wiring, Do not
change spacing between a component and the
printed-circuit board. Check the AC power cord for
5) Components, parts, and/or wiring that appear to
have overheated or that are otherwise damaged
should be replaced with components, parts and/ or
wiring that meet original specifications.
Additionally, determine the cause of overheating
and/or damage and, if necessary, take corrective
action to remove any potential safety hazard.
6) Product Safety Notice-Some electrical and mechani-
cal parts have special safety-related characteristics
which are often not evident from visual inspection,
nor can the protection they give necessarily be
obtained by replacing them with components rated
for higher voltage, wattage, etc. Parts that have spe-
cial safety characteristics are identified by shading,
an (
)or a (
)on schematics and parts lists. Use
of a substitute replacement that does not have the
same safety characteristics as the recommended
replacement part might create shock, fire and/or
other hazards. Product safety is under review con-
tinuously and new instructions are issued whenev-
er appropriate.

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1-2 Servicing Precautions
CAUTION : Before servicing units covered by this
service manual and its supplements, read and follow
the Safety Precautions section of this manual.
Note : If unforseen circumstances create conflict
between the following servicing precautions and any
of the safety precautions, always follow the safety pre-
cautions. Remember: Safety First.
1-2-1 General Servicing Precautions
(1) a. Always unplug the instrument's AC power cord
from the AC power source before (1) re-moving
or reinstalling any component, circuit board,
module or any other instrument assembly, (2)
disconnecting any instrument electrical plug or
other electrical connection, (3) connecting a test
substitute in parallel with an electrolytic capaci-
tor in the instrument.
b. Do not defeat any plug/socket B+ voltage inter-
locks with which instruments covered by this
service manual might be equipped.
c. Do not apply AC power to this instrument and
/or any of its electrical assemblies unless all
solid-state device heat sinks are correctly in-
d. Always connect a test instrument's ground lead
to the instrument chassis ground before connect-
ing the test instrument positive lead. Always
remove the test instrument ground lead last.
Note : Refer to the Safety Precautions section ground
lead last.
(2) The service precautions are indicated or printed on
the cabinet, chassis or components. When servic-
ing, follow the printed or indicated service precau-
tions and service materials.
(3) The components used in the unit have a specified
flame resistance and dielectric strength.
When replacing components, use components
which have the same ratings. Components identi-
fied by shading, by(
) or by (
) in the circuit dia-
gram are important for safety or for the characteris-
tics of the unit. Always replace them with the exact
replacement components.
(4) An insulation tube or tape is sometimes used and
some components are raised above the printed
wiring board for safety. The internal wiring is
sometimes clamped to prevent contact with heat-
ing components. Install such elements as they
(5) After servicing, always check that the removed
screws, components, and wiring have been in-
stalled correctly and that the portion around the
serviced part has not been damaged and so on.
Further, check the insulation between the blades of
the attachment plug and accessible conductive
1-2-2 Insulation Checking Procedure
Disconnect the attachment plug from the AC outlet
and turn the power ON. Connect the insulation resi-
stance meter (500V) to the blades of the attachment
plug. The insulation resistance between each blade of
the attachment plug and accessible conductive
parts(see note) should be more than 1 Megohm.
Note : Accessible conductive parts include metal pan-
els, input terminals, earphone jacks, etc.