Marantz NR1501 Repair Manual

The Marantz NR1501 is a slim 5.1-channel AV receiver featuring HDMI connectivity, Dolby Digital and DTS decoding, Audyssey MultEQ room correction, 50 watts per channel, multi-room capability, and various audio/video inputs. This repair manual covers disassembly, troubleshooting, component replacement, and service procedures for qualified technicians.

1. Safety Precautions 2. Technical Specifications 3. Disassembly Procedures 4. Circuit Diagrams 5. Troubleshooting Guide 6. Component Replacement 7. Test Points & Measurements 8. Firmware Recovery 9. Reassembly Instructions 10. Service Contacts

Safety Precautions

Before attempting any repairs, observe these critical safety measures:

Precaution	Description
Power Disconnect	Always unplug unit from AC power before servicing
ESD Protection	Use anti-static wrist strap when handling PCBs
Capacitor Discharge	Discharge large capacitors before testing
Heat Management	Allow unit to cool before handling heat sinks
High Voltage Areas	Exercise caution around power supply sections

WARNING! Only qualified technicians should perform repairs. Incorrect servicing may cause electric shock or fire hazard.

Technical Specifications

Power Output: 50W x 5 channels (8 ohms, 20Hz-20kHz)
HDMI: 4 inputs, 1 output (v1.3a with Deep Color)
Audio Decoding: Dolby Digital, DTS, Dolby Pro Logic II
Room Correction: Audyssey MultEQ
Inputs: 4 digital optical, 2 digital coaxial, 6 analog audio
Video: 3 component, 4 composite inputs
Power Supply: 120V AC, 60Hz, 400W maximum
Dimensions: 17.3" W x 4.1" H x 13.8" D

Disassembly Procedures

Step-by-step disassembly for internal access:

Remove top cover: Unscrew 6 Phillips screws from top panel.
Remove front panel: Detach 4 screws and carefully disconnect ribbon cables.
Access main board: Remove shield plate securing screws.
Remove power supply: Disconnect all connectors and remove mounting screws.
Access amplifier section: Remove heat sink mounting hardware.

CAUTION! Label all connectors and take photos during disassembly for proper reassembly.

Circuit Diagrams

Reference diagrams for major sections:

Diagram	Description
Main Power Supply	Switching power supply circuit with protection
Amplifier Section	5-channel amplifier circuitry and protection
HDMI Board	Video switching and processing circuits
Digital Audio	DSP and decoding processor circuits
Control System	Microcontroller and user interface circuits

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
No power	Fuse, power supply, standby circuit	Check main fuse F001; test standby voltage; replace power supply IC
No audio output	Amplifier IC, mute circuit, DSP	Test amplifier IC voltages; check mute transistor; verify DSP operation
HDMI no signal	HDMI board, video processor	Test HDMI board power; replace video processor IC; check connections
Overheating	Heat sink, fan, bias current	Clean heat sink; check fan operation; adjust bias current
Protection mode	DC offset, short circuit, thermal	Measure DC offset at outputs; check for shorts; test thermal sensors

Component Replacement

Common replacement components and procedures:

Power transistors: Replace in matched pairs; apply thermal compound
Electrolytic capacitors: Observe polarity; use same or higher voltage rating
Fuses: Replace with exact same type and rating
IC components: Use proper desoldering techniques; avoid overheating
Connectors: Ensure proper alignment and secure connection

Note: Use genuine Marantz parts for optimal performance and reliability.

Test Points & Measurements

Critical test points for diagnosis:

Test Point	Normal Value	Purpose
TP+5V	+5.0V ±5%	Digital logic supply
TP+12V	+12.0V ±10%	Analog circuit supply
TP-12V	-12.0V ±10%	Negative rail supply
TP STBY	+3.3V	Standby power
TP PROT	0V normal, 5V protect	Protection circuit status

Firmware Recovery

Procedures for firmware issues:

Download latest firmware from Marantz support site
Connect USB storage with firmware file to service port
Enter service mode: Hold TONE + STATUS while powering on
Select firmware update from service menu
Do not interrupt power during update process

WARNING! Incorrect firmware can permanently damage unit.

Reassembly Instructions

Reverse of disassembly with additional checks:

Verify all connectors are properly seated
Ensure no cables are pinched or strained
Check heat sink mounting and thermal compound
Test unit before final assembly completion
Perform basic functionality test

Service Contacts

For technical support and genuine parts:

Marantz Service Center: 1-800-654-0523
Technical Support: [email protected]
Parts Department: [email protected]
Online Resources: www.marantz.com/service
Service Manual Updates: Check website for latest revisions

Note: This manual is for qualified service personnel only.