Marantz NR1603 Service Manual

The Marantz NR1603 is a 7.2-channel slim AV receiver featuring 80W per channel, AirPlay compatibility, network streaming capabilities, HDMI switching with 3D and Audio Return Channel, built-in Wi-Fi and Ethernet, Audyssey MultEQ auto room calibration, and multi-zone audio. Below are key sections for technical specifications, block diagrams, troubleshooting, disassembly procedures, and service adjustments.

1. Technical Specifications 2. Block Diagrams 3. Circuit Descriptions 4. Disassembly Procedures 5. PCB Layouts 6. Service Adjustments 7. Troubleshooting Guide 8. Replacement Parts List 9. Firmware Update Procedures 10. Safety Precautions 11. Schematics

Technical Specifications

Key technical parameters and performance characteristics of the Marantz NR1603 AV receiver.

Parameter	Specification
Amplifier Section	7.2 channels, 80W per channel (8Ω, 20Hz-20kHz, 0.08% THD)
Power Consumption	450W (maximum), 65W (no signal), 0.3W (standby)
HDMI Inputs/Outputs	6 inputs (1 front), 1 output (Main Zone)
Video Section	4K/3D pass-through, Deep Color, x.v.Color
Audio Section	192kHz/24-bit DACs, Dolby TrueHD, DTS-HD Master Audio
Network Features	Built-in Wi-Fi, Ethernet, AirPlay, internet radio
Dimensions (WxHxD)	440 x 105 x 377 mm
Weight	7.8 kg
Operating Voltage	AC 120V, 60Hz (USA/Canada model)
Frequency Response	10Hz-100kHz (+1/-3dB)

Block Diagrams

System architecture and signal flow diagrams for service reference.

Main System Block Diagram: Shows overall signal path from inputs to outputs
Power Supply Block Diagram: Illustrates voltage distribution and regulation
Audio Processing Block Diagram: Details DSP and amplification stages
Video Processing Block Diagram: HDMI and analog video signal routing
Network Section Block Diagram: Wi-Fi and Ethernet connectivity paths

NOTE: Refer to schematics section for detailed component-level diagrams.

Circuit Descriptions

Detailed explanations of major circuit sections and their operation.

Power Supply Circuit: Switching power supply with multiple voltage rails
Main Amplifier Circuit: 7-channel discrete power amplifier section
HDMI Board: Video switching and processing circuitry
Main CPU Board: System control and user interface processing
Network Interface Board: Wi-Fi and Ethernet connectivity circuits
Front Panel Board: Display, buttons, and IR receiver circuits

CAUTION! High voltage present in power supply section - discharge capacitors before servicing.

Disassembly Procedures

Step-by-step instructions for accessing internal components.

Remove top cover: Remove 6 screws from rear and sides
Remove front panel: Detach 4 screws and disconnect ribbon cables
Access main board: Remove shield and disconnect all connectors
Remove HDMI board: Detach mounting screws and flex cables
Access power supply: Remove heatsink and transformer mounting hardware
Replace amplifier modules: Desolder and install new modules as needed

WARNING! Always disconnect AC power before disassembly. Use anti-static precautions.

PCB Layouts

Main Board: Component placement and trace routing diagram
Power Supply Board: High-voltage section layout with safety clearances
HDMI Board: High-speed digital signal routing
Front Panel Board: Display and control interface layout
Network Board: RF and digital interface component placement
Test Points: Location of all service test points and voltages

Service Adjustments

Factory calibration and adjustment procedures for optimal performance.

DC Offset Adjustment: Adjust VR801-VR807 for 0mV ±5mV at speaker terminals

Bias Current Adjustment: Set VR851-VR857 for 10mV across emitter resistors

HDMI Output Level: Verify proper signal levels using test patterns

Audio Calibration: Use Audyssey setup microphone for room correction

Network Settings: Configure IP address and wireless connectivity

Troubleshooting Guide

Common service issues and diagnostic procedures.

Symptom	Possible Cause	Corrective Action
No power	Power supply failure	Check fuse F1001, diodes D1001-D1004, IC1001
No audio output	Amplifier section	Verify speaker relays, check amplifier ICs, test audio inputs
HDMI no signal	HDMI board failure	Check HDMI ICs, verify 5V supply to HDMI ports
Network not working	Network board	Test Ethernet PHY, check Wi-Fi module, verify firmware
Overheating	Thermal protection	Clean heatsinks, check fan operation, verify bias current
Display issues	Front panel board	Check display driver IC, verify ribbon cable connections

Replacement Parts List

Authorized replacement components and part numbers.

Part Number	Description	Qty
IC1001	Power Supply IC	1
TR1001-TR1004	Power Transistors	4
F1001	Main Fuse (6.3A)	1
IC2001-IC2007	Amplifier ICs	7
IC3001	HDMI Switch IC	1
IC4001	Main CPU	1
DISP1001	Front Display	1
REM1001	Remote Control Sensor	1

Firmware Update Procedures

Methods for updating receiver firmware to latest version.

Network Update: Connect to internet and select "Firmware Update" in menu
USB Update: Download firmware to USB drive and insert in front port
Serial Update: Use service port with RS-232 cable for factory updates
Recovery Mode: Hold "Standby" + "Info" during power-on for recovery

WARNING! Do not interrupt power during firmware update - may cause permanent damage.

Safety Precautions

Essential safety guidelines for service technicians.

Always disconnect AC power before servicing. Discharge large capacitors. Use isolation transformer when testing live circuits. Follow ESD precautions. Verify proper grounding. Use specified replacement parts only.

DANGER! Lethal voltages present in power supply section. Only qualified technicians should perform internal repairs.

Schematics

Complete circuit diagrams for all major sections.

Main Schematic: Overall system connectivity and power distribution
Power Supply Schematic: Detailed AC/DC conversion circuits
Amplifier Section: 7-channel audio amplification circuits
HDMI Interface: Digital video input/output processing
Control System: Microprocessor and user interface circuits
Network Interface: Ethernet and wireless connectivity schematics

Service Support: Contact Marantz technical support at 1-800-270-2744 or visit www.marantz.com