Marantz PMD222 Service Manual

The Marantz PMD222 is a professional portable cassette recorder featuring three-head configuration, Dolby B/C noise reduction, manual recording level control, pitch control, line/mic inputs with phantom power, built-in speaker, AC/DC operation, and professional-grade transport mechanism. This service manual covers technical specifications, disassembly procedures, circuit diagrams, alignment instructions, and troubleshooting for qualified service technicians.

1. Technical Specifications 2. Mechanical Disassembly 3. Circuit Diagrams 4. PCB Layouts 5. Alignment Procedures 6. Test Points & Voltages 7. Component Replacement 8. Troubleshooting Guide 9. Parts List 10. Safety Precautions

Technical Specifications

Detailed electrical and mechanical specifications for the PMD222 professional cassette recorder.

Parameter	Specification
Frequency Response	30Hz - 18kHz (Metal tape)
Signal-to-Noise Ratio	72dB (Dolby C)
Wow & Flutter	0.04% (WRMS)
Input Sensitivity	Mic: 0.25mV, Line: 50mV
Output Level	Line: 0.5V, Headphone: 30mW
Power Requirements	9V DC or 120V AC adapter
Dimensions	268 x 95 x 215mm
Weight	2.2kg (with batteries)
Heads	3-head configuration (erase/record/playback)
Motors	DC servo capstan motor + DC reel motor

Mechanical Disassembly

Step-by-step disassembly procedure for accessing internal components.

Remove battery compartment cover and batteries.
Remove 6 Phillips screws from bottom case.
Carefully separate top and bottom cases.
Disconnect internal ribbon cables and connectors.
Remove transport mechanism mounting screws.
Lift out main PCB assembly for component access.

WARNING! Discharge capacitors before servicing. Handle ribbon cables carefully to avoid damage.

Circuit Diagrams

Complete schematic diagrams for all circuit sections.

Power Supply: Regulated ±12V and +5V circuits
Record/Playback Amplifier: Three-head amplification stages
Dolby NR Circuits: B and C noise reduction ICs
Motor Control: Capstan servo and reel motor drivers
Meter Driver: VU meter amplification circuits
Input/Output: Mic preamp and line buffer stages

PCB Layouts

Printed circuit board component placement and routing diagrams.

Main PCB component side - component locations and values
Main PCB solder side - trace routing and test points
Front panel PCB - switches, pots, and indicator circuits
Power supply PCB - regulator components and filtering

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

Alignment Procedures

Factory alignment steps for optimal performance.

Alignment	Procedure	Test Equipment
Playback Level	Adjust PB level for 315Hz 250nWb/m	Audio generator, oscilloscope
Record Bias	Set bias for max output at 10kHz	Audio generator, VTVM
Head Azimuth	Align for max output at 6.3kHz	Test tape, oscilloscope
Dolby Level	Set for 200mV at Dolby test point	Audio generator, VTVM
Motor Speed	Adjust for 3000Hz playback	Speed test tape, counter

Test Points & Voltages

Critical test point locations and expected voltage readings.

TP1 (Power): +12V ±0.5V
TP2 (Power): -12V ±0.5V
TP3 (Regulator): +5V ±0.1V
TP4 (Dolby): 200mV ref level
TP5 (Bias): 85kHz oscillator output
TP6 (Motor): 4.5V servo reference

CAUTION! Use high-impedance meter for accurate measurements.

Component Replacement

Special instructions for critical component replacement.

Record/Playback heads: Use alignment jigs for proper installation
Capstan motor: Lubricate shaft with specified grease
Belts: Use exact replacement parts for proper torque
Electrolytic capacitors: Observe polarity markings
ICs: Use anti-static precautions during handling

WARNING! Head replacement requires complete realignment.

Troubleshooting Guide

Common problems and solutions for the PMD222.

Symptom	Possible Cause	Corrective Action
No power	Faulty power switch, regulator	Check DC input, replace Q101-Q103
Poor high frequency	Head wear, azimuth misalignment	Replace head, realign azimuth
Speed variation	Worn belt, motor issues	Replace belt, check motor supply
Distorted recording	Bias oscillator, recording amp	Check Q201-Q204, bias adjustment
No Dolby action	IC failure, level misadjustment	Replace IC201/202, recalibrate

Parts List

Complete component listing with manufacturer part numbers.

Heads: Marantz PX-222 (Record/Playback)
Capstan Belt: FBM-12.0
Motors: Matsushita EG-510EDF (capstan)
IC201: CX20188 (Dolby processor)
IC202: LA6458S (dual op-amp)
Transistors: 2SC1815, 2SA1015 (general purpose)

Safety Precautions

Important safety information for service personnel.

WARNING! Disconnect power before servicing. Use isolation transformer when testing live circuits. Observe ESD precautions with MOS devices. Replace safety critical components with exact specifications.

Service Notes: This manual is for qualified technicians only. Marantz professional products division, support available through authorized service centers.