Yamaha dsp a780

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DIGITAL SOUND FIELD PROCESSING AV AMPLIFIER

DS P-A780

SERV CE MANUAL

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IMPORTANT NOTICE \

This manual has been provided for the use of tuthorized YAMAHA Retailers rind their service personnel.
It has been assumed that basic service procedures inherent to the industry, and more specifically YAMAHA
Products, are already known and understood by the users. And have therefore not been resumed

WARNING: Failure to follow appropriate service and safety procedures when servicing this product
may result in personal injury. darn-nation of expensive components Ind failure of tire
product to perform as specified. For these retsnns. we advise III YAMAHA product owners
that Ill service inquired should be performed by In Iuihoriud YAMAHA Retailer or the
Appointed service representative.

IMPORTANT: The presentation or sale of this manual to any individual or firm doet not conninrte
authorization. certification or recognition of any spplicable technical capabilities, or
emblisli a principle-agent relationship of my form

The data provided is believed to be accursie and applicable to the unit(s) 'Iidicaicd on the cover The reierdi,
engineering and service departments of YAMAHA ue ooriiiniially striving to improve YAMAHA products
Modificttiont Lie. therefore. inevitable Ind specifications nre subject to change without notice or obligation to
retrofit. Should any discrepancy appear to exist, pleue contact the distributors Service Division,

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

IMPORTANT: 'nirri the unit OFF during disusernbly and parts replacement. Recheck all work before you
\ lwa power to die uniir j

I CONTENTS

TO SERVICE PERSONNEL
REAR PANELS ...................

SPECIFICATIONS ......................... .
PROGRAM PARAMETER TABLE .4
INTERNAL VIEW ,5

DISASSEMBLY PROCEDURES
DIAGNOSTICS MODE ...............
PROTECTION FUNCTION ..
IC DATA ...........................

BLOCK DIAGRAM .................
PRINTED CIRCUIT BOARD ..
DISPLAY DATA .. ....................
TEST POINT WAVEFORMS ..
IC BLOCKS
SCHEMATIC DIAGRAM ..
PARTS LIST ....................
REMOTE CONTROL TRANSMITTER ................. .

YAOMAHA COR RATIO
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3.2k-752 n© Printed in Japan. 94.4

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DSP-A780

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). :I )-

When service has been completed, it is imperative to verily ® I
that all exposed conductive surfaces are properly insulated _

from supply clrcuits.

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

e Leakage current must not exceed 0.5mA.

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

INSULATING
TABLE

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 ol 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 SOLDEFI, ELECTRICAL/ELECTRONIC OH PLASTIC COMPONENTS IN YOUR MOUTH FOR
ANY REASON WHATSOEVER!

Avoid prolonged, unprotected contact between solder and your skinl 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 REAR PANELS

V U, C models

mm: was
""- 12::
032mm

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V R model