marantz sr8500 service manual pdf

The Marantz SR8500 is a high-performance AV receiver featuring Dolby Digital and DTS decoding, 7-channel amplification, multiple audio/video inputs, advanced DSP processing, and comprehensive connectivity options. This service manual provides detailed technical information for qualified service technicians including schematics, block diagrams, troubleshooting procedures, and component specifications.

Technical Specifications

Detailed electrical and mechanical specifications for the Marantz SR8500 AV receiver.

Parameter	Specification
Power Output	110W x 7 channels (8Ω, 20Hz-20kHz, 0.08% THD)
Frequency Response	10Hz - 100kHz (+1/-3dB)
Total Harmonic Distortion	0.08% (20Hz-20kHz at rated power)
Signal-to-Noise Ratio	100dB (IHF-A weighted)
Input Sensitivity	200mV (line inputs)
Digital Inputs	Coaxial x 3, Optical x 3
Video Inputs	Composite x 4, S-Video x 4, Component x 2
Audio Inputs	7.1 channel analog, Phono, CD, DVD, etc.
Power Consumption	650W maximum
Dimensions	440 x 465 x 185mm (W x D x H)

Block Diagrams

System architecture and signal flow diagrams for service analysis.

1. Main System Block Diagram: Shows overall signal path from inputs to outputs.
2. Digital Audio Processing Block: Details DSP and decoding circuits.
3. Power Supply Block Diagram: Illustrates voltage regulation and distribution.
4. Amplifier Section Block: Shows 7-channel amplifier architecture.
5. Control System Block: Microprocessor and user interface circuits.

WARNING! For qualified technicians only. Incorrect interpretation may cause equipment damage.

Circuit Descriptions

Detailed explanations of major circuit sections and their operation.

1. Power Supply Circuit: Switching power supply with multiple voltage rails.
2. Digital Audio Board: 24-bit/192kHz DACs and DSP processing.
3. Amplifier Circuits: Discrete power amplifier stages for each channel.
4. Video Processing: Component video upconversion and processing.
5. Control Circuit: Main microprocessor and system control logic.

CAUTION! High voltages present in power supply section. Disconnect power before servicing.

Disassembly Procedures

• Top Cover Removal: Remove 6 screws from rear panel and sides.
• Front Panel Assembly: Disconnect ribbon cables carefully.
• Main Board Access: Remove shield plates and mounting screws.
• Power Supply Board: Discharge capacitors before handling.
• Amplifier Heat Sink: Thermal compound replacement procedure.
• Reassembly: Reverse order with proper cable routing.

Test Points & Measurements

Access service mode and perform critical measurements for proper operation.

Service Mode Access: Press TONE and SURROUND simultaneously on front panel while powering on.

Key Test Points: +5V STBY, +12V analog, ±15V audio, +45V amplifier supply, speaker output DC offset (<50mV).

Measurement Procedures: Power output verification, distortion analysis, frequency response testing, signal level measurements at various circuit points.

Troubleshooting Flowcharts

Systematic approach to diagnosing common problems.

Symptom	Possible Cause	Corrective Action
No power	Power supply failure	Check AC input, fuse F001, standby supply IC601
No audio output	Amplifier/mute circuit	Verify speaker relay operation, check mute transistors
No video	Video processor	Test video IC voltages, check video switching
Digital inputs not working	Digital receiver circuit	Verify clock signals, check digital receiver IC
Overheating	Thermal protection	Check fan operation, verify bias current settings

Parts List & Replacement

Critical components and replacement guidelines.

1. Power Transistors: 2SC5200/2SA1943 output pairs - replace in sets.
2. Power Supply ICs: STR-G6653 switching regulator - check surrounding components.
3. Digital Processors: Replace with exact part number due to firmware.
4. Electrolytic Capacitors: Check for bulging/leaking, replace with same specifications.
5. Fuses: Use correct current rating and timing characteristics.

Tip: Always verify replacement parts meet original specifications.

PCB Layouts

Printed circuit board diagrams for component location and trace routing.

Includes: Main board component side and solder side, power supply board, front panel board, amplifier board layouts with component designators matching schematics.

WARNING! Use anti-static precautions when handling PCBs. Damage from ESD may not be immediately apparent.

Alignment Procedures

Factory adjustment procedures for optimal performance.

DC Offset Adjustment: Measure speaker terminals and adjust VR for <10mV DC.

Bias Current Adjustment: Set idle current to specified value for each channel.

DSP Processor Settings: Factory preset restoration and calibration procedures.

Video Level Alignment: Component video output level and color calibration.

Safety Precautions

Essential safety information for service personnel.

High voltage warnings: Power supply contains lethal voltages even when unplugged. Discharge large capacitors before servicing.

Component handling: Use proper tools and techniques to avoid damage to sensitive components.

Test equipment: Use isolated test equipment and follow proper grounding procedures.

Service Notes

Additional technical information and common repair notes.

Service Bulletin	Description	Application
SB-8500-001	Power supply capacitor replacement	Units with buzzing noise
SB-8500-002	DSP firmware update procedure	Digital audio dropout issues
SB-8500-003	Thermal pad replacement	Overheating in high ambient temperatures
SB-8500-004	Input selector switch cleaning	Intermittent input selection

Technical Support: Marantz Service Department for authorized service centers only.

Document Revision: Version 2.1 - Updated component specifications and troubleshooting procedures.