LG DRD-8080B User manual

3
INTRODUCTION
GENERAL FEATURE
SPECIFICATIONS
1. SUPPORTED SYSTEM
• IBM Compatible Pentium 133MHz or Above (with PIO mode 4, TX chip set recommended)
2. SUPPORTED OS
3. GENERAL PERFORMANCE
• Data Transfer Rate ...........................................................................................Sustained Data Transfer Rate
DVD (Outer side) : Approx. 10,800 kbytes/sec
DVD (Inner side) : Approx. 4,725 kbytes/sec
CD (Outer side) : Approx. 6,000 kbytes/sec
CD (Inner side) : Approx. 2,625 kbytes/sec
• Data Buffer Capacity.......................................................................................................................512 kbytes
• Access Time...................................................................Random Access DVD : 120ms Typical (8X)
CD : 100ms Typical (40X)
4. POWER REQUIREMENTS
• Voltage ........................................................................................................................................+5V DC +5%
+12V DC +5%
• Ripple .....................................................................................................................................+5V : 100mVp-p
+12V : 100mVp-p
• Current .........................................................................................+12V : 400mA (Average), 0.9A (Maximum)
+5V : 500mA (Average), 1.2A (Maximum)
5. AUDIO PERFORMANCE
• Frequency Response......................................................................................................20Hz~20KHz(+ 3dB)
• S/N Ratio (IHF-A+20kHZ LPF) ..........................................................................88 dB (Typical at 1 KHz 0dB)
80 dB (Limit at 1 KHz 0dB)
• T.H.D. (IHF-A+20kHZ LPF)...............................................................................0.05% (Typical at 1 KHz 0dB)
0.15% (Limit at 1 KHz 0dB)
• Channel Separation (IHF-A+20kHZ LPF) .................................................................................75 dB(Typical)
70 dB(Limit)
• Output Voltage (1kHz 0dB) 47KΩLoad ..................................................................................0.8Vrms +20%
• Headphone Level (1kHz 0dB) 33ΩLoad.................................................................................0.8Vrms +20%
•Enhanced IDE interface
•Internal 5.25 inch, halfheight DVD-ROM Drive
•120ms (Typical) Random Access Time (DVD)
•100ms (Typical) Random Access Time (CD)
•Supports 8X (max) Rotational Modes in DVD Mode
•Supports 40X (max) Rotational Modes in CD Mode
•Max 10,800 kB/sec Sustained Transfer rate in DVD mode
•Max 6,000 kB/sec Sustained Transfer rate in CD mode
•Photo-CD Multisession Disc Spec compliant
•Multimedia MPC-3 Spec compliant
•Power Tray Loading/Ejection Mechanism
•3-Way Eject Support (Software, Open/Close Button,
Emergency Eject)
•Closed Enclosure
•Built-in ATAPI Interface Controller
•Software Volume Control
•Easy CD-Audio Play front panel Controls
•Front panel Volume Control for Headphone Output
•Built-in MODE-1 ECC/EDC
•MTBF (125,000H) POH (at 10% Utilization)
•PIO Mode 4 & Multiword DMA Mode 2 Support
•ULTRA DMA 33 support
•Horizontal/Vertical Mounting
•Digital audio output connector
•Digital audio through ATAPI Interface
•Spin-down Mode for energy saving
•MS-DOS (Ver 3.1 or Higher)
• Windows 3.1/95/98/2000
• Windows NT (Ver 4.0)
• OS/2 Warp (Ver 3.0)
• Solaris (Ver 2.4 or Higher)
• Linux ’96 Slacware (Ver 3.1.0)
This service manual provides a variety of service
information. It contains the mechanical structure of
the DVD-ROM Drive together with mechanical
adjustments and the electronic circuits in schematic
form. This DVD-ROM Drive was manufactured and
assembled under our strict quality control standards
and meets or exceeds industry specifications and
standards.

4
LOCATION OF CUSTOMER CONTROLS
(1) Digital Audio Ouput Connector
This is a digital audio output or Video CD output
connector.
You can connect this to a digital audio system or a
Video CD Board.
(2) Analog Audio Output Connector
The Audio Output Connector connects to a sound
card.
(3) Master/Slave/CSEL Jumper
These three jumpers are used to set the DVD-ROM
Drive to either a Master, Slave, or CSEL device.
(4) Interface Connector
This 40-pin connector is used to transfer data and
control signals between the DVD-ROM Drive and your
PC.
(5) Power-in Connector
Attach a power cable from the computer to this
connector.
COMPACT
COMPACT
1243
ROM
ROM
ROM
ROM
5 6
DIGITAL ANALOG
INTERFACE POWER
DR CSM
SLA
GLG39 1
+5 +12
GND
40
2
AUDIO AUDIO
125
4
3
FRONT VIEW
BACK VIEW
(1) Headphone Jack
Standard 1/8″(3.5mm) stereo jack for listening to the
audio signal from audio CDs.
(2) Headphone Volume Control
Adjusts the headphone sound level.
(3) Disc Drawer
Accepts a CD-ROM/DVD-ROM disc on its tray.
(4) Busy Indicator
The Busy Indicator lights during initialization and data-
read operations.
(5) Emergency Eject Hole
Insert a paper clip here to eject the drawer manually or
when there is no power.
(6) Open/Close/Stop Button
This button is pressed to open or close the CD tray.
If an audio CD is playing, pressing this button will stop
it, and pressing it again will open the tray.

1. CABINET and CIRCUIT BOARD
DISASSEMBLY
1-1. Bottom Mecha
A. Release 4 screws (A) and remove the Bottom Mecha
in the direction of arrow (1). (See Fig.1-1)
1-2. Front Bezel Assy
A. Insert and press a rod in the Emergency Eject
Hole and then the CD Tray will open in the direction
of arrow (2).
B. Remove the Tray Door in the direction of arrow
(3) by pushing the stoppers forward.
C. Release 3 stoppers and remove the Front Bezel Assy.
1-3. Cabinet and Main Circuit Board
A. Remove the Cabinet in the direction of arrow (4).
(See Fig. 1-3)
B. Remove the CD Tray drawing forward, by pushing
the Hook(a) backward(5).
C. Remove the Main Circuit Board in the direction of
arrow (6).
D. At this time, be careful not to damage the 4
connectors, are positioned at side, of the Main
Circuit Board.
2. DECK ASSY DISASSEMBLY
2-1. Base Assy
A. Release 1 screw (C) and 2 Stoppers (D).
B. Separate the Base Assy in the direction of arrow (7).
C. Remove the Frame Assy Up/Dowm.
(3)
(2)
Tray Door
Stoppers
CD Tray
Emergency Eject Hole
Front Bezel Assy
(A)
(A)
(A)
(A)
(1)
Bottom Mecha
Fig. 1-1
DISASSEMBLY
5
(4)
(5)
(6)
Hook (a)
Cabinet
Main
Circuit Board
Fig. 1-3
Fig. 1-2
(8)
(7)
Mechanism Assy
(C)
(D)
(D)
Base Assy
Frame Assy Up/Down
Fig. 1-4

6
2-2. Pick-up Unit
A. Remove the skew spring.
B. Remove the Pick-up Unit.
2-3. Feeding Motor Assy
A. Remove the Feeding Motor Assy by pushing the 2
hooks(b).
B. At this time, be careful the hooks of the Base Pick-up.
Skew Spring
Pick-up Unit
Fig. 1-5
Base Pick-up
Feeding Motor Assy
Fig. 1-6

INTERNAL STRUCTURE OF THE PICK-UP
1. Structure of the Pick-Up
10
C001
C002 CN14 DVD PD VCC
CN10 DVD PD VC
CN15 DVD PD GND
CN8 DVD A
CN9 DVD B
CN11 DVD C
CN12 DVD D
CN7 DVD RF
CN13 DVD E
CN5 DVD F
CN19 DVD VR
CN18 DVD MD
CN16 DVD LD
CN15 DVD LD GND
CN1 FO+
CN2 FO-
CN3 TR+
CN4 TR-
CN30 CD VCC
CN20 CD VC
CN26 CD GND
CN25 CD A
CN28 CD B
CN23 CD C
CN24 CD E
CN29 CD F
CN21 CD VR
CN22 CD MD
CN27 CD LD
C010
C011
C012
VR02
U002
U001
TRACKING
FOCUS
C004
ACTUATOR
VR01
LASER DIODE
LASER DIODE
PICK UNIT

11
1) Focus Error Signal –> (A + C) - (B+C)
•In case of CD Disc
This signal is generated in RF AMP IC (IC301 : SSI3723) and controls the pick-up’s up and down to
focus on CD Disc.
2) Tracking Error Signal (3-Beam Method) –> F - E
•In case of CD Disc
This signal is generated in RF AMP IC (IC301 : SSI3723) and controls the pick-up’s left and right shift to
find the track on CD Disc.
3) RF Signal –> A+B+2C
•In case of CD Disc
This signal is converted to DATA signal in DSP IC (IC701 : CXD3030R).
2. Structure of the Photo Diode (CD)
Infrared laser
Pick-Up module
Photo Diode Tracking
Focusing
(As seen from light
receiving side)
E
C
B
F
A

12
1) Focus Error Signal –> (A+C) - (B+D)
•In case of DVD Disc
This signal is generated in RF AMP IC (IC301 : SSI3723) and controls the pick-up’s up and down to
focus on DVD Disc.
2) Tracking Error Signal (DPD Method) –> Differential phase of (A+C) and (B+D)
•In case of DVD Disc
This signal is generated in RF AMP IC (IC301 : SSI3723) and controls the pick-up’s left and right shift to
find the track on DVD Disc.
3) RF Signal –> A+B+C+D
•In case of DVD Disc
This signal is converted to DATA signal in DSP IC (IC201 : CXD1867R).
3. Structure of the Photo Diode (DVD)
(As seen from light
receiving side)
Red laser
Pick-Up module
Photo Diode Tracking
Focusing
F
D
C
B
A
E

13
PN301
18
19
16
R317
R318
C332
C335
Q302
C331
C333
CD LD
CD PD
DVD LD
IC301 SSI3723
DVD PD
Q303
R315
R316
Vcc5V
Vcc5V
22
27
DVD-
MD
DVD-
VR
DVD-
LD
LD
LD
CD-
PD
CD-VR
CD-
LD
DVD-LD(LASER DIODE)
CD-LD(LASER DIODE)
PICK-UP Unit
Monitor
Diode
Monitor
Diode
22
24
21
23
21
1-2. APC Circuit Operation
It drives the LD to the constant current and adjusts the LD input current , so that the output current is
constant.
IC301 (SSI3723) Pin , : PD IN, Monitor Input of Laser diode APC
IC301 (SSI3723) Pin , : LD OUT, External Current Driver Control output of the LD (Laser Diode)
The detect current from the monitor diode converts to the I/V (Current/Voltage) at the external resistor.
Beforehand, it adjusts a fixed level over for a standard GND.
If this voltage inputs to the PD IN (IC301 Pin 23, 24), it is amplified about 36.4 times (about 31.2dB).
So this voltage outputs from the LD OUT (IC301 Pin 21, 22).
The LD driving element (Q302/Q303) uses the TR more than 200hfe, and controls LD OUT (IC301 Pin 21,
22) connected to the base of Q302/Q303.
The APC control for the each DVD/CD sets Register of the IC301 (SSI3723) according to Disc in the
µ-COM.
DESCRIPTION OF CIRCUIT
1. APC (Automatic Power Control) Circuit
1-1. APC Circuit Constitution
23 24
21 22

14
E
A
BC
F
F
D
C
B
A
E
23
25
28
8
9
24
34
29
1
7
CD (A, B, C)
DVD RF
17
18
64
56
910
11 12
13 14
15 16 AMP
AMP
MUX ATT
AGC
AGC
40
GCA
GCA
SUM
AMP
BUFF
MUX
MUX
FE
TE
RF AC
To IC701 38
To IC701 36
To IC701 47
To IC202 117
GCA 39
57
EQ Phase
Detector
EQ
DVD (A, B, C, D)
DVD
(A
2 , B 2 , C 2 , D 2 )
CD (E, F)
Pick-up Unit
PN301
IC301
SSI3723
4
4
RF DC
RF SIN
63
2. RF Amplifier Circuit
2-1. RF AMP Constitution

15
FOCUS & TRACKING SERVO PROCESS
SLED(Feed) SERVO PROCESS
F
F
D
C
B
A
B
A
E
E
C
Pick - Up
IC301
RF AMP
SSI3723
5
CD
E-F
(A. B. C. E. F)
6
DVD(A. B. C. D.)
TE/
DPD TE
SELECTOR
FE
Generating
DPD TE
Generating
TE
FOCUS
ERROR
DETECTOR
FOCUS &
TRACKING
ACTUATOR
IC501
DRIVE
BA5983FM
IC701
CD/DVD SERVO & DSP
CXD3030R
F+ F-T+ T-
LEVEL SHIFT
LEVEL SHIFT
FAO
TAO
D/A
DIGITAL
EQUALIZER
(AUTO ADJUSTMENT
CIRCUIT)
SLED
Control
Signal
A/D
TE FE
TE
SAO
SLED MOTOR
Hall Sensor
M
PHO - C
PHO - A
FEED. MOTOR+
FEED. MOTOR-
LEVEL SHIFT
IC501
Q501
DRIVE
BA5983FM
KTD1304
+
IC201
u-COM
SLGNCHG
SLED CLK
(A. B. C)
(A. B. C.D)
(A
2 . B 2 . C 2 .D 2 )
3. Focus/Tracking/Sled Servo Circuit
3-1. FOCUS, TRACKING & SLED SERVO PROCESS