Yamaha yst sw150

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ACTIVE SERVO PROCESSING
SUBWOOFER SYSTEM

7 YST-. W150

SERVICE MANUAL

/ IMPORTANT NOTICE \

This manual has been provided for the use of authorized YAMAHA
Retailers and their service personnel,

It has been assumed that basic service procedures inherent to the industry,
and more specifically YAMAHA Products, are already known and under-
stood by the users, and have therefore not been restatedr

WARNING: Failure to follow appropriate service and safety proce»
dures when servicing this product may result in per-
sonal injury, destruction of expensive components, and
failure of the product to perform as specified, For these
reasons. we advise all YAMAHA product owners that
any service required should be performed by an autho-
rized YAMAHA Retailer or the appointed service rep-
rescntative.

IMPORTANT: The presentation or sale of this manual to any indi»
vidual or firm does not constitute authorization, certi-
fication or recognition of any applicable technical
capabilities. or establish a principle-agent relationship
of any form.

The data provided is believed to be accurate and applicable to the unit(s)
indicated on the cover. The research, engineering, and service depart-
ments of YAMAHA are continually striving to improve YAMAHA prod-
ucts. Modifications are. therefore, inevitable and specifications are subject
to Change without notice or obligation to retrofiti Should any discrepancy
appear to exist, please contact the distributors Service Division,

WARNING: Static discharges can destroy expensive components.
Discharge any static electricity your body may have
accumulated by grounding yourself to the ground buss
in the unit (heavy gauge black wires connect to this
buss).

IMPORTANT: Turn the unit OFF during disassembly and part replace-
ment. Recheck all work before you apply power to the
unit.

I CONTENTS

TO SERVICE PERSONNEL . 1 BLOCK DIAGRAM.
INTERNAL VIEW .. 1 IC BLOCKS

REAR PANELS -2 PRINTED CIRCUIT BOARD.
SPECIFICATIONS 2 SOHEMATIC DIAGRAM 10
DISASSEMBLY PROOEDURES ------- ----- 3 PARTS LIST..... ......... ...... 11~17
ADJUSTMENTS

............ .............3

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YAMAHA CORPORATION
P.O.Bo><1 ,Hamamatsu,Japan

341K»061 IE ® Printed in Japan 9510

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YST-SW1 50

I TO SERVICE. PERSONNEL

1. Critical Components Information. AC LEAKAGE

Components having special characteristics are marked and WALL EQUIPMENT TESTER OR
must be replaced with parts having specifications equal to OUTLET UNDER TEST EQUIVALENT
those originally installed.

2. Leakage Current Measurement (For 120V Models Only). ® 3
When service has been completed, it is imperative to verity
that all exposed conductive surfaces are properly insulated :
from supply circuits. _ INSfiLéENG

0 Meter impedance should be equivalent to 1500 ohm shunted
by 0.15uF.

o Leakage current must not exceed 0.5mA.

0 Be sure to test for leakage with the AC plug in both
polarities.

WARNING: CHEMICAL CONTENT NOTICE!

The solder used in the production of this product contains LEAD. In addition, other electrical/electronic
and/or plastic (where applicable) components may also contain traces of chemicals found by the
California Health and Welfare Agency (and possibly other entities) to cause cancer and/or birth defects
or other reproductive harm.

DO NOT PLACE SOLDER, ELECTRICAL/ELECTRONIC OR PLASTIC COMPONENTS IN YOUR MOUTH
FOR ANY REASON WHATSOEVER!

Avoid prolonged, unprotected contact between solder and your skin! When soldering, do not inhale
solder fumes or expose eyes to solder/flux vapor!

If you come in contact with solder or components located inside the enclosure of this product, wash
your hands before handling food.

I INTERNAL VIEW

O 0
O
0
o P.C.B. MAIN (3)
9 P.C.B. MAIN (1)
o 9 P.C.B. MAIN (2)
o 0 POWER TRANSFORMER
9 ,
0
O 0