Yamaha MX-2000 Service Manual

ERE0 POWER AMPLIFIER
CONTENTS
f
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 inhennt to the industry, and more specifically Yamaha
Products, are already known and understcad 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 Eamponentr and failure of the
product
to perform as specified. For these reasons, we advise all Yamaha product ownel
rhat all sewib~ required should be performed by an authorized Yamaha Retailer or th
appointed service representative.
IMPORTANT: The presentation or sale of this manual to any individual or firm does not ~onstitute
authorization, certification or remgnitidn of any appllcaMe technical aapabillties, or
establish a principle-agent relationship of any form.
The data provided is believed to be accurate and applicable to the unit(s) iddftxtted an the wver. The
research, engineering, and service departments of
Yamaha are continually striving to imptwe Yamaha
products. Modifications are, therefore, inevitable and specifications are subjectt~ chaage wi&out notice or
obligation to retrofit. Should any discrepancy appear
to exist, please contact the distributor's Servim
Division.
WARNING: Static discharges can destroy expensive components. Discharge any staticelectricity your
body may have accumulated by grounding yourself to the ground buss in the unit (heavy
gauge black wires
c~lncct to this buss).
IMPORTANT: Turn the unit OFF during d~sassembly and parts replacement. Recheck all work before
you apply
power to the unit.
L - -
- -
TO SERVICE PERSONNEL ................. 1 ADJUSTMENTS ........................ 4
FRONTIREAR PANELS ................... 1 PRINTED CIRCUIT BOARD ............. 5 - 9
SPECIFICATIONS ....................... 2 SCHEMATIC DIAGRAM .................. 10
BLOCK DIAGRAM ...................... 2 WIRING.. ........................... 11
INTERNAL
VIEW.. ..................... 3 PARTSLIST.. .................... 12-20
DISASSEMBLY PROCEDURES
.............. 4
YAMAHA CORPORATION
PO.Box 1. Harnarnatsu. Japan
1.35K-604 liq@ Printed in Japan '88.8

Yamaha MX-2000 Specifications

General

Type	Stereo Power Amplifier
Weight	25 kg
Total Harmonic Distortion	0.003% (20Hz - 20kHz)
Damping Factor	150
Input Sensitivity	1.23V
Signal to Noise Ratio	125dB

Summary

TO SERVICE PERSONNEL

Critical Components Information

Components marked 'A' require exact replacement for specified performance and safety.

Leakage Current Measurement

Post-service check to ensure proper insulation of exposed conductive surfaces from supply circuits.

SPECIFICATIONS

Performance Specifications

Detailed technical specifications including output power, frequency response, and distortion levels.

BLOCK DIAGRAM

Amplifier Functional Block Diagram

Illustrates the main functional blocks and signal flow within the amplifier.

INTERNAL VIEW

DISASSEMBLY PROCEDURES

Top Cover Assembly Removal

Front Panel Removal Steps

ADJUSTMENTS

Idling Voltage Adjustment

Procedure to adjust VR201 for correct idling voltage on the main circuit board.

Power Meter Calibration

Steps to adjust VR401/VR402 and VR403/VR404 for accurate power meter readings.

PRINTED CIRCUIT BOARD (Main Circuit Board)

Main Circuit Board Pattern Side Layout

Shows the pattern side layout of the main circuit board, indicating component placement.

PRINTED CIRCUIT BOARD (Power Supply Circuit Board 1)

Power Supply Circuit Board (1) Pattern Side Layout

Displays the pattern side layout for the first power supply circuit board.

PRINTED CIRCUIT BOARD (Power Supply Circuit Board 2)

Power Supply Circuit Board (2) Pattern Side Layout

Displays the pattern side layout for the second power supply circuit board.

PRINTED CIRCUIT BOARD (Meter Circuit Board 2 / Protection Circuit Board)

PRINTED CIRCUIT BOARD (Input Circuit Board / Meter Circuit Board 1)

WIRING

Internal Wiring Diagram

Illustrates the wiring connections between major internal components and boards.

PARTS LIST (Electrical - Section 1)

Electrical Parts: Capacitors

Lists various types of capacitors with part numbers and specifications.

Electrical Parts: Resistors

PARTS LIST (Electrical - Section 2)

Electrical Parts: Transistors and ICs

EXPLODED VIEW

Unit Assembly Exploded Diagram