Marantz DP870 Service Manual

The Marantz DP870 is a professional-grade CD player featuring advanced digital processing, high-quality audio components, precision transport mechanism, and comprehensive service capabilities. This service manual provides detailed technical information for qualified service technicians, including schematics, alignment procedures, troubleshooting guides, and replacement parts lists for proper maintenance and repair.

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

Technical Specifications

Detailed technical specifications for the Marantz DP870 professional CD player.

Parameter	Specification
Frequency Response	2Hz - 20kHz (±0.5dB)
Signal-to-Noise Ratio	>110dB
Dynamic Range	>100dB
Total Harmonic Distortion	<0.002%
Channel Separation	>100dB (1kHz)
Output Level	2.0V RMS
Digital Output	Coaxial, Optical
Power Requirements	120V/230V AC, 50/60Hz
Power Consumption	25W
Dimensions	440 x 105 x 360mm (WxHxD)
Weight	8.5kg

Block Diagrams

System block diagrams showing signal flow and component relationships.

Main System Block Diagram: Shows overall system architecture
Digital Signal Processing Block Diagram: DSP and decoding paths
Power Supply Block Diagram: Voltage regulation and distribution
Servo Control Block Diagram: Focus and tracking servo systems
Audio Output Block Diagram: Analog audio processing stages

NOTE: Refer to schematic diagrams for detailed component-level information.

Circuit Descriptions

Detailed descriptions of major circuit sections and their functions.

Laser Pickup Assembly: Optical system with focus and tracking mechanisms
RF Amplifier: Processes signal from photodiodes
Servo Processors: Controls spindle motor, sled motor, and focus/tracking
Digital Signal Processor: EFM demodulation, error correction, and digital filtering
D/A Converter: High-quality 24-bit digital-to-analog conversion
Analog Output Stage: Low-noise op-amps and filtering circuits
Power Supply Unit: Multiple regulated voltage outputs
Microcontroller System: System control and user interface

Disassembly Procedures

Step-by-step disassembly instructions for service access.

Remove top cover: Remove 6 screws from rear and sides
Remove front panel: Disconnect ribbon cables and remove 4 screws
Access main PCB: Remove shield and disconnect all cables
Remove transport mechanism: Disconnect flex cables and remove mounting screws
Access power supply: Remove AC inlet and transformer mounting hardware

WARNING! Disconnect AC power before disassembly. Handle laser assembly with care.

Alignment & Adjustment

Factory alignment procedures and adjustment points.

Adjustment	Procedure	Test Equipment
Laser Power	Adjust VR501 for 0.45mW at test point	Laser power meter
Focus Offset	Adjust VR102 for minimum jitter	Oscilloscope
Tracking Balance	Adjust VR101 for symmetrical eye pattern	Oscilloscope
PLL Free-run Frequency	Adjust VC101 for 4.3218MHz ±10Hz	Frequency counter
Output Level	Adjust VR201 for 2.0V RMS at 1kHz	Audio analyzer

Troubleshooting Guide

Systematic troubleshooting procedures for common faults.

Symptom	Possible Cause	Corrective Action
No power	Power supply fault, fuse blown	Check F001 (2A), measure +5V, +12V outputs
No disc recognition	Laser assembly, spindle motor	Check laser emission, clean lens, test spindle motor
Skip or mistracking	Dirty lens, servo adjustment	Clean optical path, check tracking error signal
No audio output	DAC, output stage, muting circuit	Check DAC clock, test op-amps, check mute transistors
Display issues	Display driver, microcontroller	Check VFD voltage, test data lines to display

Parts List

Complete list of replacement parts and components.

Laser Pickup: KSS-213C or equivalent
Spindle Motor: SF-92.5S-10250 or compatible
Main ICs: CXD2545Q (DSP), PCM1716 (DAC), MN662741 (Servo)
Power Transistors: 2SC3852, 2SA1492
Op-Amps: NJM4580 or equivalent
Fuses: F001 (2A), F002 (1A)
Belts: Loading belt FRX-2.0
Capacitors: Various values as per schematic

PCB Layouts

Printed circuit board layouts and component locations.

Main PCB (PWB-1234-A): Component side and solder side views
Power Supply PCB (PWB-5678-B): Component placement and routing
Front Panel PCB (PWB-9012-C): Display and control circuits
Transport PCB (PWB-3456-D): Servo and motor drive circuits

NOTE: All dimensions in millimeters. Ground planes indicated by cross-hatching.

Wiring Diagrams

Interconnection diagrams and cable routing information.

Main Harness: Power supply to main board connections
Front Panel Harness: Control and display wiring
Transport Harness: Laser pickup and motor connections
Audio Output Harness: RCA and digital output wiring
Power Input Harness: AC inlet to power supply connections

CAUTION: Observe proper cable routing to avoid interference and mechanical stress.

Safety Precautions

Important safety information for service personnel.

Always disconnect AC power before servicing
Use isolation transformer when testing live circuits
Observe ESD precautions when handling semiconductors
Laser safety: Do not view laser beam directly
High voltage caution: Power supply contains hazardous voltages
Use specified replacement parts only
Reassemble completely before applying power

WARNING! Laser radiation - avoid direct exposure to laser beam.

Service Notes

Additional service information and technical notes.

Factory service mode entry: Hold STOP + PLAY during power-on
Test point locations and normal voltage values
Common modifications and updates
Compatibility with other Marantz models
Firmware version identification and update procedures
Recommended test discs and calibration media
Service center contact information and support resources

Service Support: Contact authorized Marantz service centers for technical assistance and genuine parts.