RECORD OF REVISIONS
VERSION	NOTES
1	ORIGINAL ISSUE July, 1995

Model Name	Serial No.
MDH-10	1,000,001 thru 3,000,000 (UC2) 3,000,001 thru 4,000,000 (J1) 4,000,001 thru 5,000,000 (CEJ) 5,000,001 thru 6,000,000 (CEK)

TABLE OF CONTENT

SECTION 1 INTRODUCTION

1-1 CONFIGURATION OF SERVICE MANUAL
1-2 CAUTION
1-3 SWITCHES

1-3-1 SCSI ID Select
1-3-2 Terminator
1-3-3 POWER Mode Select
1-3-4 AVLS

SECTION 2 TOOLS AND MEASUREMENT INSTRUMENTS

2-1 GENERAL AND SPECIAL TOOLS

2-1-1 General Tools
2-1-2 Special Tools
2-1-3 Test Discs (Disks)
2-1-4 Measuring Equipments
2-1-5 Expendable and Chemical Supplies

2-2 SPECIAL TOOLS

2-2-1 Pin Board Ass'y and Fixture Base
2-2-2 Error Rate Counter (MD)
2-2-3 RF Buffer Board
2-2-4 RS-232 Interface 3V
2-2-5 Discs

2-3 Q/L SYSTEM SETTING AND CONFIGURATION

2-3-1 Set Up Q/L System
2-3-2 System Configuration

SECTION 3 TROUBLESHOOTING

3-1 BEFORE TROUBLESHOOTING
3-2 PROCEDURE OF ATP TEST 1

3-2-1 Preparing
3-2-2 Test Procedure
3-2-3 Check Point

3-3 AUDIO FUNCTION CHECK

3-3-1 Serial Control
3-3-2 Audio Mode

3-4 PROCEDURE OF ATP TEST 2

3-4-1 Pre-Setting
3-4-2 Test Procedure
3-4-3 Check Point

3-5 FUNCTION CHECK (OTHER THAN AUDIO BLOCK)

3-5-1 Pre-Setting
3-5-2 Status Check
3-5-3 Disc ID Switches
3-5-4 Sled Motor Check
3-5-5 Focusing
3-5-6 Tracking
3-5-7 Spin Up
3-5-8 Seek
3-5-9 Read Cluster
3-5-10 Read TOC/UTOC
3-5-11 Write Cluster
3-5-12 2 Axis Actuator
3-5-13 Optical Device Signals
3-5-14 CLV Control
3-5-15 Disc Type and Tracking Mode Selection
3-5-16 Write Signal
3-5-17 Stepper Motor

SECTION 4 PARTS REPLACEMENT

4-1 UPPER PANEL AND REAR/BOTTOM PANEL ASS'Y REPLACEMENT
4-2 ORNAMENTAL BELT ASS'Y REPLACEMENT
4-3 CONNECTOR PLATE REPLACEMENT
4-4 MAM MOUNTED BOARD REPLACEMENT
4-5 DC-DC CONVERTER REPLACEMENT
4-6 MECHANICAL DECK (MECH DECK) COVER ASS'Y REPLACEMENT
4-7 FRONT/REAR FRAME ASS'Y, BATTERY CASE ASS'Y AND MECH DECK REPLACEMENT
4-8 COMPONENTS ON MECHANICAL DECK (MECH DECK) REPLACEMENT

4-8-1 REC Flexible Cable and MD Flexible Cable
4-8-2 OP Head Ass'y
4-8-3 Gear (Worm Wheel) and Mechanical Compartment (Mech Con) Mounted Board
4-8-4 Motor
4-8-5 Gear Chassis Block Ass'y
4-8-6 SLED Motor Block Ass'y
4-8-7 Holder Ass'y
4-8-8 REC Mounted Board Ass'y

SECTION 5 ADJUSTMENT, MEASURING AND CHECK

5-1 BEFORE ADJUSTMENT AND MEASURING
5-2 ELECTRICAL ADJUSTMENT

5-2-1 Pre-Setting
5-2-2 TEMP Compensation
5-2-3 Laser Power Adjustment
5-2-4 Focus Offset Adjustment
5-2-5 EF Phase Difference Check
5-2-6 Tracking Offset Adjustment
5-2-7 Gain Adjustment
5-2-8 RF Adjustment
5-2-9 Error Rate Measurement
5-2-10 Motor Jitter Measurement

5-3 VOLTAGE OUTPUT MEASUREMENT

5-3-1 Power Supplying from LIP-12 Rechargeable Battery (Lithium-ion Battery Pack)
5-3-2 Power Supplying from AC Adapter
5-3-3 Regulator Function Check

5-4 CPU DIGITAL CHECK
5-5 PWM AMP CHECK
5-6 SPINDLE MOTOR CHECK
5-7 AUDIO OUTPUT LEVEL CHECK
5-8 DOWNLOAD PROGRAM
5-9 OPTICAL DEVICE CLEANING

5-9-1 Cleaning with Lens Cleaner

SECTION 6 EXPLODED VIEWS AND LIST

6-1 MECHANICAL ASS'Y LOCATION

6-1-1 Overall Ass'y
6-1-2 Switches Setting for shipping

6-2 BLOCK DIAGRAM

6-2-1 Block Diagram
6-2-2 Interconnection Diagram

6-3 PARTS LAYOUT AND CIRCUIT DIAGRAM

6-3-1 MAM-F2 Mounted Board
6-3-2 MECH-CON Mounted Board

6-4 ELECTRICAL PARTS

SECTION 7 SEMICONDUCTORS PIN ASSIGNMENT

WARNING

OPTICAL PICK-UP BLOCK (KMS-190A) USING PRECAUTIONS As the laser diode in the optical pick-up is easily damaged by static electricity, make a solder bridge on the laser tap of the flexible board when transporting or disconnecting from the connector of the board. Also carry out thorough anti static electricity measures. Handle the flexible board carefully as it is damaged easily.

WARNING

It may be possible that the OP Head Ass'y in the unit is damaged, if the Mech Deck itself turns upside down. In order to avoid such trouble during function checks, use some pillows as below.