Yamaha AX-390 Service Manual

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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
persona)
injury, destruction of expensive components, and failure
of the
product
to
perform
as
specified.
For
these reuons, we advise all YAMAHA
product
owners
that any service
required
should be
performed
by an
authorized
YAMAHA Retailer
or the
appointed
service representative.
IMPORTANT:
The
presentation
or sale of this manuai
to any
individual
or
firm
does not constitute
authorization, certification 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 departments
of YAMAHA
are continually striving to improve YAMAHA
products.
Modifications are, therefore,
inevitable and specifications
are subject to change
without notice
or obligation
to
retrofit.
Should
any discrepancy
appear
to exist,
please
contact the distributorrs 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
pan replacement.
Recheck all
work
before
you
apply
power
to the unit.
PIN
CONNECTTON DTAGRAM
..............5
PRTNTED
CIRCU|T BOARD ...........
6-11
BLOCK DIAGRAM
.,,12-13
lC BLOCKS
12-13
SCHEMATIC DIAGRAM
14-15
PARTS 1rST.............
.16-23
REMOTE
CONTROL TRANSMITTER........-......,,.,..24
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Printed in
Japan
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www.hifiengine.com

Yamaha AX-390 Specifications

General

Power Output	40W per channel (8 ohms, 20Hz-20kHz, 0.04% THD)
Frequency Response	10Hz-100kHz (+0/-3dB)
Signal-to-Noise Ratio	100dB (CD input)
Input Sensitivity	2.5mV (MM), 150mV (line)
Dimensions	435 x 151 x 388mm (W x H x D)
Weight	8.5 kg
Total harmonic distortion	0.04% (20Hz-20kHz, 40W, 8 ohms)
Damping factor	100
Total Harmonic Distortion (THD)	0.04%
Signal to noise ratio	100 dB

Summary

To Service Personnel

Important Service Notice

Critical warnings and disclaimers for authorized service personnel.

Service Safety Warnings and Precautions

Critical warnings on safety procedures, static discharge, and proper handling.

Rear Panel Layout

Rear Panel Configurations (R, B, G Models)

Details the rear panel connections and configurations for different model variants.

AC Leakage Test Setup

Technical Specifications

Audio Section Specifications

Detailed performance metrics for the audio circuitry.

General and Power Specifications

Power supply, consumption, dimensions, and weight details.

Internal Component Layout

Disassembly and Reassembly Procedures

Unit Disassembly Steps

Step-by-step guide for dismantling the amplifier unit.

Idling Current Adjustment

Microcomputer (µ-COM) Data

µ-COM Pinout and Port Functions

Detailed pin assignments and functions for the µ-COM IC.

Test Point Waveform Analysis

Component Pin Connection Diagrams

Integrated Circuit (IC) Pinouts

Pin connection diagrams for various integrated circuits used.

Diode and Transistor Pinouts

Pinouts for diodes and transistors.

Printed Circuit Board Layout (Operation Section)

PCB Operation Section Component Locations

Locations of semiconductors on the Operation PCB.

Printed Circuit Board Layout (Operation Sections 2 & 3)

Printed Circuit Board Layout (Operation Section 4 & Main Section 2)

Printed Circuit Board Layout (Operation Sections 5 & 6, Main Section 1)

Printed Circuit Board Layout (Main Section 2 - J, B, G Models)

Printed Circuit Board Layout (Main Section 2 - R Model, Main Section 4)

System Block Diagram

Integrated Circuit Block Diagrams

Multiplexer/Demultiplexer IC Block Diagrams

Block diagrams for TC4052BP and TC4053BP multiplexer ICs.

Op-Amp and Motor Driver IC Block Diagrams

Block diagrams for NJM2068L-D Op-Amp and LB1641 Motor Driver ICs.

Schematic Diagram (Operation Section)

Schematic Diagram (Operation Sections 2, 3, 4)

Schematic Diagram (Tone Control Section)

Schematic Diagram (Operation Section continuation)

Schematic Diagram (System Control Section)

Schematic Diagram (Operation Sections 5 & 6)

Schematic Diagram (Muting Circuit)

Schematic Diagram (Power Amplifier Section)

Schematic Diagram (Main Section 3)

Remote Control Transmitter Schematic

Schematic Diagram (Main Section 1 & 2, Power Supply)

Schematic Diagram (Main Section - Protection Circuit)

Electrical Parts List

Component Abbreviations and Definitions

List of abbreviations used for electrical components in the parts list.

Electrical Component Listings

Comprehensive list of electrical components with part numbers and descriptions.

Main PCB Component List (Part 1)

Main & Operation PCB Component List (Part 2)

Operation PCB Component List (Part 1)

Operation PCB Component List (Part 2)

Exploded View of Unit Assembly

Mechanical Parts List

Mechanical Parts List (Front Panel, Chassis, Buttons)

List of mechanical components including front panel parts, chassis, and buttons.

Mechanical Parts List (Screws and Accessories)

Remote Control Key Functions

Carbon Resistor Part Numbers