1 Safety precautions 5
1.1. General guidelines 5
2 Prevention of Electrostatic Discharge (ESD) to Electrostatic
Sensitive (ES) Devices 6
3 Precaution of Laser Diode 7
4 Handling the Lead-free Solder 7
4.1. About lead free solder (PbF) 7
5 Each Button 8
6 New Feature 10
6.1. Quick start function(REC) 10
7 Taking out the Disc from RAM-Drive Unit when the Disc
cannot be ejected by OPEN/CLOSE button 11
7.1. Forcible Disc Eject 11
7.2. When the Forcible Disc Eject can not be done. 11
8 Service Explorer 12
9 Self-Diagnosis and Special Mode Setting 15
9.1. Self-Diagnosis Functions 15
9.2. Special Modes Setting 16
9.3. Service Modes 19
10 Assembling and Disassembling 24
10.1. Disassembly Flow Chart 24
10.2. P.C.B. Positions 24
10.3. Top Case 25
10.4. Front Panel 25
10.5. SD Card P.C.B. 25
10.6. Digital P.C.B. 25
10.7. DVD-RAM Drive 26
10.8. HDD 26
10.9. LED P.C.B. 27
10.10. Power P.C.B. 28
10.11. Rear Panel 28
10.12. Front (L) P.C.B. 29
10.13. Main P.C.B. 29
10.14. Tuner P.C.B. and Nicam Decoder P.C.B. 30
11 Service Fixture and Tools 31
12 Service Positions 31
12.1. Checking and Repairing of Power P.C.B. 31
12.2. Checking and Repairing of Digital P.C.B. 32
12.3. Checking and Repairing of Main P.C.B. 33
12.4. Checking and Repairing of DVD-RAM Drive 34
12.5. Checking and Repairing of HDD 35
13 Caution after replacing parts 36
13.1. After replacing the RAM Drive with new one 36
13.2. When the unit does not operate normally after replacing
the Timer Microprocessor or Main P.C.B. 36
14 Standard Inspection Specifications after Making Repairs 36
15 Voltage and Waveform Chart 37
15.1. Power P.C.B. 37
15.2. Main P.C.B. 37
15.3. Tuner P.C.B. 39
15.4. LED P.C.B. 39
15.5. P9001 Connector 40
15.6. Waveform Chart 41
16 Abbreviations 42
17 Block Diagram 45
17.1. Power Supply Block Diagram 45
17.2. Analog Video Block Diagram 47
17.3. Analog Audio Block Diagram 48
17.4. Timer Block Diagram 49
18 Schematic Diagram 51
18.1. Interconnection Schematic Diagram 51
18.2. Power Supply Schematic Diagram 52
18.3. Main Net Section (Main P.C.B. (1/3)) Schematic Diagram
(M) 54
18.4. A/V I/O Section (Main P.C.B. (2/3)) Schematic Diagram
(AI) 56
18.5. Timer Section (Main P.C.B. (3/3)) Schematic Diagram (T)
58
18.6. Tuner Pack Schematic Diagram 60
18.7. Nicam Decoder Schematic Diagram 61
18.8. SD Card Schematic Diagram 62
18.9. LED Schematic Diagram 63
19 Print Circuit Board 65
19.1. Power P.C.B. 65
19.2. Main P.C.B. 66
19.3. Tuner P.C.B., LED P.C.B., Front (L) P.C.B. 71
19.4. Nicam Decoder P.C.B. 72
19.5. SD Card P.C.B. 73
20 Exploded Views 75
20.1. Casing Parts & Mechanism Section 75
20.2. Packing & Accessories Section 76
21 Replacement Parts List 77
CONTENTS
Page Page
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DMR-EH50EB / DMR-EH50EG / DMR-EH50EP / DMR-EH52EG
