Marantz SR-19 Service Manual

The Marantz SR-19 is a high-performance audio/video receiver featuring Dolby Digital and DTS decoding, multiple audio/video inputs, advanced surround sound processing, AM/FM tuner, and comprehensive connectivity options. This service manual provides detailed technical information for qualified service technicians including schematics, alignment procedures, troubleshooting guides, and replacement parts information.

1. Technical Specifications 2. Block Diagrams 3. Circuit Descriptions 4. Disassembly Procedures 5. Alignment & Adjustment 6. Troubleshooting Guide 7. Parts List 8. Schematics 9. PCB Layouts 10. Safety Precautions 11. Service Notes

Technical Specifications

Complete technical specifications and performance characteristics of the Marantz SR-19 receiver.

Parameter	Specification
Power Output	100W x 5 channels (8Ω, 20Hz-20kHz, 0.08% THD)
Frequency Response	10Hz - 100kHz (+1/-3dB)
Signal-to-Noise Ratio	100dB (line input)
Total Harmonic Distortion	0.08% (20Hz-20kHz at rated power)
Input Sensitivity	200mV (line), 2.5mV (MM phono)
Digital Inputs	3 optical, 2 coaxial
Analog Inputs	6 line, 1 phono, 1 tape
Video Inputs	3 composite, 2 S-video, 1 component
Dimensions	440mm x 161mm x 418mm (WxHxD)
Weight	12.5kg

Block Diagrams

System block diagrams showing signal flow and functional relationships between major circuit sections.

Main System Block Diagram - Overall signal routing and processing
Power Supply Block Diagram - AC/DC conversion and distribution
Audio Processing Block Diagram - Digital/analog signal paths
Video Processing Block Diagram - Video switching and enhancement
Tuner Section Block Diagram - AM/FM reception and processing

WARNING! These diagrams are for qualified service personnel only. Do not attempt repairs without proper training.

Circuit Descriptions

Detailed descriptions of major circuit sections and their operation.

Power Supply Circuit: Switching power supply with multiple regulated outputs
Main Amplifier Circuit: Discrete power amplifier stages with protection circuits
Digital Processing Circuit: DSP-based audio decoding and processing
Tuner Circuit: PLL-synthesized AM/FM tuner with quartz filtering
Control Circuit: Microprocessor-based system control and user interface

CAUTION! High voltages present in power supply section. Use isolation transformer during service.

Disassembly Procedures

Step-by-step instructions for safe disassembly and reassembly.

Top Cover Removal: Remove 6 screws from rear panel and slide cover backward
Front Panel Removal: Disconnect ribbon cables after removing top cover
Main Board Access: Remove shield covers and disconnect all connectors
Power Supply Board: Discharge main capacitors before servicing
Heat Sink Removal: Remove power transistors and thermal compound

Alignment & Adjustment

Factory alignment procedures and adjustment points.

Adjustment	Procedure	Test Equipment
DC Offset	Adjust VR501-VR505 for 0mV ±5mV	Digital Multimeter
Bias Current	Adjust VR601-VR605 for 15mA ±2mA	Milliammeter
FM Tuner Alignment	Adjust L101, L102 for maximum sensitivity	FM Signal Generator
AM Tuner Alignment	Adjust T101 for peak performance	AM Signal Generator
Dolby Level	Adjust VR201 for 200mV reference	Audio Analyzer

Troubleshooting Guide

Systematic troubleshooting procedures for common failures.

Symptom	Possible Cause	Corrective Action
No power	Power supply failure	Check F901 (5A), D901-D904, Q901-Q904
No audio output	Protection circuit activated	Check DC offset, speaker shorts, thermal protection
Distorted sound	Amplifier bias incorrect	Adjust bias current per section 6 procedures
No digital processing	DSP circuit failure	Check IC701 power supply and clock signals
Tuner not working	Tuner circuit fault	Verify +12V supply to tuner module

Parts List

Complete listing of replacement parts with manufacturer part numbers.

Power Transistors: 2SC5200 / 2SA1943 (Q601-Q610)
Main Filter Capacitors: 10000μF/63V (C901, C902)
Output Relays: MY4-02-DC24 (RLY501-RLY505)
Power Supply IC: STR-G6653 (IC901)
Main Processor: HD6437043F20 (IC001)
DSP Chip: YSS918 (IC701)
Tuner Module: TNR-E9001 (TU001)

Schematics

Complete schematic diagrams for all circuit boards.

Main Amplifier Schematic - Power amplifier and protection circuits
Power Supply Schematic - Switching power supply and regulation
Pre-amplifier Schematic - Input selection and volume control
Digital Board Schematic - DSP and digital processing circuits
Control Board Schematic - Microprocessor and display circuits
Tuner Schematic - AM/FM tuner and IF stages

NOTE: Schematics are for reference only. Actual measurements may vary.

PCB Layouts

Printed circuit board layouts and component placement diagrams.

Main Board - Component side and solder side views
Power Supply Board - Component placement and trace routing
Front Panel Board - Switch and display layout
Digital Board - DSP and memory chip placement
Tuner Board - RF circuit layout

Tip: Use these layouts for component identification and trace following.

Safety Precautions

Critical safety information for service technicians.

DANGER! Lethal voltages present in power supply section. Always disconnect AC power before servicing. Use isolation transformer for live measurements. Discharge main filter capacitors before working on power supply. Follow electrostatic discharge (ESD) precautions when handling integrated circuits.

Service Notes

Important service tips and common repair procedures.

Service Note	Description
Protection Mode	Unit enters protection if DC offset exceeds ±2V or thermal overload
Factory Reset	Hold TUNER PRESET + SURROUND MODE while powering on
Service Mode	Press DISPLAY + STATUS + SURROUND MODE simultaneously
Firmware Update	Requires special interface cable and software
Warranty Info	2 years parts and labor from date of purchase

Service Support: Contact Marantz Technical Support at 1-800-654-6633 or visit www.marantz.com