Marantz SR4001 Service Manual

The Marantz SR4001 is a high-performance AV receiver featuring 7.1 channel surround sound, 90 watts per channel, HDMI connectivity, Dolby Digital and DTS decoding, multi-room audio capability, AM/FM tuner with 40 station presets, and advanced audio calibration. This service manual provides comprehensive technical information for qualified service technicians including schematics, block diagrams, troubleshooting guides, and repair procedures.

1. Technical Specifications 2. Block Diagrams 3. Circuit Descriptions 4. Disassembly Procedures 5. Test Points & Measurements 6. Alignment Procedures 7. Troubleshooting Flowcharts 8. Parts List & Replacement 9. PCB Layouts 10. Safety Precautions 11. Service Notes

Technical Specifications

Complete technical specifications for the Marantz SR4001 AV receiver.

ParameterSpecification
Power Output90W x 7 (8Ω, 20Hz-20kHz, 0.08% THD)
Frequency Response10Hz-100kHz (+1/-3dB)
Total Harmonic Distortion0.08% (20Hz-20kHz at rated power)
Signal-to-Noise Ratio100dB (IHF-A)
Input Sensitivity200mV (line), 500μV (FM tuner)
HDMI Inputs3 inputs, 1 output (version 1.1)
Digital Inputs2 optical, 2 coaxial
Analog Inputs6 stereo pairs
Video Inputs3 composite, 2 component
Power Consumption550W maximum, 65W standby
Dimensions440 x 414 x 171 mm (W x D x H)
Weight12.5 kg

Block Diagrams

System block diagrams showing signal flow and major components.

  1. Main System Block Diagram: Overview of entire receiver architecture
  2. Audio Processing Section: DSP, DAC, and analog audio paths
  3. Power Supply Section: Switching power supply and regulation
  4. Video Processing: HDMI, component, and composite video paths
  5. Control System: Microprocessor and user interface
  6. Tuner Section: AM/FM tuner block diagram
  7. Amplifier Section: 7-channel power amplifier blocks

NOTE: Refer to schematic diagrams for detailed circuit information.

Circuit Descriptions

Detailed descriptions of major circuit sections and their operation.

WARNING! High voltages present in power supply section. Exercise caution.

Disassembly Procedures

Step-by-step instructions for disassembling the receiver.

  1. Remove top cover: Unscrew 6 Phillips screws on rear panel
  2. Remove front panel: Disconnect ribbon cables carefully
  3. Access main board: Remove 8 screws securing main PCB
  4. Remove amplifier heatsink: Detach after removing power transistors
  5. Access power supply: Remove SMPS board after discharging capacitors
  6. Front panel disassembly: Remove knobs and buttons systematically

CAUTION! Always disconnect AC power before disassembly. Discharge large capacitors.

Test Points & Measurements

Critical test points and measurement procedures for service diagnostics.

Test PointLocationNormal ValueTolerance
TP1 (+12V)PSU board near IC501+12.0V DC±5%
TP2 (-12V)PSU board near IC502-12.0V DC±5%
TP3 (+5V)Main board near IC101+5.0V DC±3%
TP4 (OSC)Main board X10116.9344MHz±100ppm
TP5 (REF)Main board IC201 pin 232.5V DC±2%
TP6 (BIAS)Amp board VR7018.5mV DC±1mV
TP7 (PROTECT)Main board Q601 collector0V (normal)-

Alignment Procedures

Factory alignment and adjustment procedures for optimal performance.

  1. FM Tuner Alignment: Adjust L101, L102 for maximum sensitivity
  2. AM Tuner Alignment: Adjust T101, T102 for peak performance
  3. Amplifier Bias Adjustment: Set VR701 for 8.5mV across emitter resistors
  4. DC Offset Adjustment: Adjust VR1-VR7 for 0mV DC output
  5. DSP Calibration: Use service mode for digital processor alignment
  6. Protection Circuit Test: Verify proper operation of all protection systems

IMPORTANT: Use specified test equipment and follow procedures exactly.

Troubleshooting Flowcharts

Systematic troubleshooting guides for common failure modes.

SymptomDiagnostic StepsLikely Causes
No powerCheck AC input, fuse F001, standby voltageBlown fuse, failed rectifier, SMPS fault
Protection modeCheck DC offset, output transistors, thermal sensorShorted outputs, bias failure, overheated
No audioVerify input selection, check DAC output, preamp stageFailed DAC, mute circuit, processor fault
HDMI no signalCheck HDMI board power, input detection, EDIDHDMI chip failure, firmware issue
Tuner no receptionVerify antenna, check tuner IC supply voltagesTuner IC failure, alignment needed
Distorted audioCheck bias current, output transistors, power supplyBias misadjustment, failing transistors

Parts List & Replacement

Complete parts list with replacement part numbers and cross-references.

PCB Layouts

Printed circuit board layouts for all major assemblies.

  1. Main PCB Top Layer: Component placement and routing
  2. Main PCB Bottom Layer: Solder side and ground plane
  3. Power Supply Board: High voltage section layout
  4. Amplifier Board: Output stage and heatsink mounting
  5. Front Panel Board: Display and control interface
  6. HDMI Board: Separate video processing module

NOTE: All layouts shown at 1:1 scale for accurate component location.

Safety Precautions

Critical safety information for service personnel.

WARNING! Lethal voltages present. Only qualified technicians should perform service.

Service Notes

Important service notes and common repair issues.

IssueSolutionReference
Protection circuit activationCheck output transistors and DC offsetSection 8, page 24
HDMI handshake failureUpdate firmware, check EDID ROMService Bulletin 07-12
Display dim or segments missingReplace VFD, check filament voltageSection 9, part VFD-001
Intermittent audio dropoutResolder DSP and DAC ICs, check clocksTechnical Note TN-408
OverheatingClean heatsink, check bias current, verify fanSection 7, procedure 4
Remote control issuesReplace sensor, check 5V supply to front panelSection 9, part IRS-001

Service Support: Marantz Technical Support: 1-800-370-3745 | www.marantz.com/service

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