Yamaha PortaTone PSR-270 User Manual

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■CONTENTS
SPECIFICATIONS ......................................................................................3
PANEL LAYOUT .......................................................................................4
CIRCUIT BOARD LAYOUT .......................................................................5
BLOCK DIAGRAM .................................................................................... 6
DISASSEMBLY PROCEDURE .................................................................7
LSI PIN DESCRIPTION .......................................................................... 12
IC BLOCK DIAGRAM ............................................................................. 14
CIRCUIT BOARDS .................................................................................. 15
TEST PROGRAM & INITIALIZE ...............................................................17
PANEL VOICE LIST .................................................................................19
GM VOICE LIST....................................................................................... 20
STYLE LIST .............................................................................................21
MIDI IMPLEMENTATION CHART............................................................22
PARTS LIST
PANEL SWITCH TABLE
OVERALL CIRCUIT DIAGRAM
SERVICE MANUAL
PK 001617
HAMAMATSU,JAPAN
1.95K-504 I Printed in Japan’99.03

Yamaha PortaTone PSR-270 Specifications

General

Voices	100
Styles	100
MIDI	Yes
Type	Portable Keyboard
Number of Keys	61
Effects	Reverb, Chorus, DSP
Display	LCD
Power Supply	PA-3B adapter
Tones	12
Connections	Headphone, MIDI In/Out, Sustain Pedal, DC In
Polyphony	32-note
Demo Songs	5

Summary

Important Safety and Handling Notices

Product Handling and Safety Warnings

Provides essential warnings for safe operation, maintenance, and chemical content.

Product Specifications

Voice, Accompaniment, and Control Features

Lists voice capabilities, auto accompaniment functions, and overall control features.

Panel Layout and Controls

Control Panel and Rear Panel Layout

Illustrates and describes the layout of the control panel and rear panel connectors.

Circuit Board Layout and Wiring

System Block Diagram

Disassembly Procedure: Initial Steps

Circuit Board Disassembly

LCD and EL Light Disassembly

Speaker and Keyboard Assembly Disassembly

Keyboard Assembly Reassembly

LSI Pin Description

LCD Driver and CPU Pinouts

LSI Pin Description: Tone Generator

Tone Generator IC Pin Descriptions

IC Block Diagrams

Operational Amplifier and D/A Converter Diagrams

Circuit Board Layouts: DM and MKS3

Circuit Board Layouts: Amplifier and PSV

Test Program and Initialization

Test Program Preparation and Execution

Guides on entering, proceeding through, and executing the product's test program.

Test Program Details and Data Initialization

Test Program Checks and Factory Reset

Details on test program results, RAM backup checks, and factory data initialization.

MIDI Implementation Chart

Parts List Overview

Parts List Sections Overview

Circuit Diagrams 1/2 (DM,AM/PN)

Circuit Diagrams 2/2 (MKS3,MK-H,MK-L)