Yamaha c160 c320 c450 power amp service manual

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POWER AMPLIFIER

SERVICE MANUAL

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ICONTENTS

SPECIFICATIONS ..................................................................... 3
PANEL LAYOUT ........... 4
DIMENSIONS .............. 5
BLOCK DIAGRAM ...................................... 5
CIRCUIT BOARD LAYOUT 8. WIRING .. ..... 6
DISASSEMBLY PROCEDURE ..................... 10
IC BLOCK DIAGRAM ............................................................... 12
POWER CONSUMPTION vs OUTPUT POWER GRAPH ....... 12
CAUTION FOR SPEAKER CONNECTION ............................. 12
CIRCUIT BOARDS ........................................... 13

INSPECTIONS ................... 16
TROUBLESHOOTING ............................................................. 18
PARTS LIST

OVERALL CIRCUIT DIAGRAM

PA- .YAMAHA

HAMAMATSU,JAPAN
o.411<.4o41 @Primed 1.. Japan '982

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C1SO/C3ZOIC450

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 understood by the users, and have therefore not been restated.

WARNING: Failure to follow appropriate service and safety procedures when servicing this product
may result in personal injury, destruction of expensive components and failure of the
product to perform as specified. For these reasons, we advise all Yamaha product
owners that all service required should be performed by an authorized Yamaha Retailer
or the appointed service representative.

IMPORTANT: The presentation or sale of this manual to any individual or firm does not constitute
authorization, certification, recognition of any applicable technical capabilities, or establish
a principal-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 departments of Yamaha are continually striving to improve Yamaha
products. Modifications are, therefore, inevitable and changes in specification are subject to change
without notice or obligation to retrofit. Should any discrepancy appear to exist, please contact the dis-
tributors 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 parts replacement. Recheck a_H work before
you apply power to the unit.

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 WHAT SO EVER!

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 WARNING
Components having special characteristics are marked A and must be replaced with parts having
specification equal to those originally installed.