Sansui 350A Service Manual

Page 2

CONTENTS

M

GENERAL TROUBLESHOOTING CHART ................ 3, 4
DISASSEMBLY PROCEDURE .................................... 5
BLOCK DIAGRAM ................................................ 6
ALIGNMENT .............................................. 7, 8, 9, 10
SCHEMATIC DIAGRAM .................................... 11, 12
PRINTED CIRCUIT BOARDS AND PARTS LIST
...................... 13, 14, 15, 16, 17, 18, 19, 20, 21

OTHER PARTS AND THEIR POSITION ON CHASSIS
.................................................... 21, 22

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GENERAL TROUBLESHOOTING OHART

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If the amplifier is otherwise operating satisfactorily
the more common causes of trouble may generally
be attributed to the following:

1. Incorrect connections or loose terminal contacts.
Check the speakers, record player, tape deck.
antenna and line cord.

2. Improper operationi Before operating any audio

instructions.

3. Improper location of audio components. The
proper positioning of components, such as speak-
ers and turntable, is vital to stereo.

4. Defective audio components.

Following are some other common causes of mal-

component, be sure to read the manufacturers

function and What to do about them.

PROGRAM SYMPTOM PROBABLE CAUSE WHAT TO 00
AM, FM or a. Constant or intermit- * Discharge or oscillation l * Attacha noise limiter to the elec-
MPX reception tent _noise heard at caused by electrical appli- trical appliance that causes the noise,
certain times or in a ances, such as fluorescent ~ or attach it to the power source of
certain area. lamps, TV sets. DC: mo- I . the amplifier.
tors, rectifier and oscillator "'f Install ' an . outdoor antenna and
Natural phenomena, such ground thenamplifier to raise the
as atmospherics, static, and v.1:signalto-noise ratio.
thunderbolt. _ ; * Reverse the power cord plug-recept-
Insufficient antenna input .acle connections.
ifilgzrrggiogzgarfénggfi * If the noise occurs at a certain fre-
the station b i quency, attacha wave trap to the
f ANT. input; _
' Wave interference rom * P1 » .' . '
~ - ace the set away from other elec-
other electrical appliances trical - a pplianceS.
b. Needle of the tuning Needle movement is not * Tune the set for maximum signal
meter does not move necessarily related to the strength;
sharply. sensitivity of the amplifier. .» W . .
c. Zero point of the meter Regional difference in field . if The unit is not at fault.
moves greatly. intensity. . ' ' . x _
AM reception a. Noise heard at a par- Natural phenomenon. V fffilnstall an antenna for maximum
ticular time of day, in antenna efliciency. See ANTEN-
a certain area or over NA in the Operating Instructions.
part Of the dial' '5* in some cases, the noise can be elim-
' inated by grounding the amplifier or
. reversing the power cord plug-re-
ceptacle connections.
i b. High-frequency noise Adjacent-channel interfer- * Although such noise cannot be elim-
ence or beat interference inated by the amplifier, it is advis~
- ' > able to turn the TREBLE control
,, . . . . . from midpoint to left.
' TV set is too closevto the * Place the TV set away from the
audio system : '> 2 audio system.

FM reception a. Noisy Poor noise limiter effect or i * Adjust the antenna (supplied) for
too lovy SN .ratio .due to maximum signal strength.
insufiiment antenna input. * If this is not effective, use an outdoor

antenna designed exclusively for

FM. When you use a TV antenna

. . L ' for both TV and FM with a splitter

NOTE: FM'reception is affected considerably by make sure TV reception is not af-

the condmons of the transmitting stations: power fected.

and antenna efficiency. As a result, you may .

receive one station quite well while having di~ * An excesswely long antenna may
fiiculty receiving another star ion. cause neise.