LG DRD-8160B Service Manual

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. 21,600 kbytes/sec DVD (Inner side) : Approx. 8,100 kbytes/sec CD (Outer side) : Approx. 7,200 kbytes/sec CD (Inner side) : Approx. 3,300 kbytes/sec

• Data Buffer Capacity.......................................................................................................................512 kbytes

• Access Time.................................................................Random Access DVD : 120ms Typical (16X)

CD : 100ms Typical (48X)

4. POWER REQUIREMENTS

• Voltage ........................................................................................................................................+5V DC +5%

+12V DC +5%

• Ripple .....................................................................................................................................+5V : 100mVp-p

+12V : 100mVp-p

• Current .........................................................................................+12V : 400mA (Average), 1.3A (Maximum)

+5V : 500mA (Average), 1.2A (Maximum)

5. AUDIO PERFORMANCE

• Frequency Response......................................................................................................20Hz~20KHz(+3dB)

• S/N Ratio (IHF-A+20kHZ LPF) ..........................................................................75 dB (Typical at 1 KHz 0dB)

70 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) 47KΩ Load ................................................................................0.75Vrms +

20%

• Headphone Level (1kHz 0dB) 33Ω Load...............................................................................0.75Vrms +

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 16X (max) Rotational Modes in DVD Mode

• Supports 48X (max) Rotational Modes in CD Mode

• Max 21,600 kB/sec Sustained Transfer rate in DVD mode

• Max 7,200 kB/sec Sustained Transfer rate in CD mode

• Photo-CD Multisession Disc Spec compliant

• DVD-R, DVD-RW, DVD dual (OTP, PTP) 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/ME/XP

• 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.

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.

ROM

COMPACT

43 5 6

FRONT VIEW

BACK VIEW

(1) Headphone Jack

Standard

″

(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 dataread 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 Chassis

A. Release 4 screws (A) and remove the Bottom

Chassis 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 it outward.

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. Release 2 hooks (a) and remove the CD Tray. C. Remove the Soldering of the LD- and LD+ (B) for

the Loading Motor, and then remove the Main

Circuit Board. D. At this time, be careful not to damage the 3

connectors of the Main Circuit Board.

2. MECHANISM ASSY

2-1. Base Pick-Unit Assy

A. Separate the Base Pick-Up Unit Assy from the

MechanismAssy. B. Release 2 screws (C) and 1hook and then

remove the Base Pick-Up Unit Assy.

DISASSEMBLY

(A)

(1)

Bottom Chassis

Fig. 1-1

Fig. 1-2

Fig. 1-3

Fig. 2-1

Cabinet

(4)

Hooks (a)

(B)

Main

Circuit Board

Tray Door

(3)

Stoppers

(2)

Emergency Eject Hole

Front Bezel Assy

CD Tray

Base Pick-up Unit Assy

Hook

(C)

Mechanism Assy

INTERNAL STRUCTURE OF THE PICK-UP

1. Structure of the Pick-Up

CN14 DVD VCC CN05 DVD VC CN08 DVD GND

CN10 DVD A CN09 DVD B

CN11 DVD C CN12 DVD D

CN06 DVD RF+

CN07 DVD RF-

CN13 DVD GND

CN17 DVD VR

CN18 DVD MD CN15 DVD LD

CN16 DVD LD GND

CN01 F+ CN02 F-

CN03 T+

CN04 T-

CN28 CD VCC

CN19 CD VC

CN20 CD GND CN26 CD A

CN27 CD B CN24 CD C CN29 CD E CN30 CD F CN25 CD RF

CN22 CD VR

CN23 CD MD CN21 CD LD

C001

X1 X1

C002

C003

VR02

TRACKING

FOCUS

Differential RF outputs circuit

HFM

ACTUATOR

VR01

L004

L002

L003

C004

VCC

RF+

A B C D

RF-

GND

Ri Rf

L001

LASER DIODE

PICK-UP UNIT

1) Focus Error Signal –> (A + C) - (B+C)

• In case of CD Disc This signal is generated in RF AMP IC (IC301 : MT1326) and controls the pick-up’s up and down to focus on CD Disc.

2) Tracking Error Signal (3-Beam Method) –> E - F

• In case of CD Disc This signal is generated in RF AMP IC (IC301 : MT1326) 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 (IC201 : MT1329).

2. Structure of the Photo Diode (CD)

Infrared laser

Pick-Up module

Photo Diode

Tracking

Focusing

(As seen from light

receiving side)

1) Focus Error Signal –> (A+C) - (B+D)

• In case of DVD Disc

This signal is generated in RF AMP IC (IC301 : MT1326) 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 : MT1326) 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 : MT1329).

3. Structure of the Photo Diode (DVD)

(As seen from light

receiving side)

Red laser

Pick-Up module

Photo Diode

Tracking

Focusing

MDI

70k

500

Vref

LD1CTL,LD2CTL

LDC1,LDC2

70k

LDO

(Vp is the central voltage of MD)

(Inside block of IC301)

DESCRIPTION OF CIRCUIT

1. ALPC (Automatic laser power control)

1-1. ALPC Circuit Constitution

Dual laser power control for DVD and CD are provided. The laser power for CD and DVD can be programmable by LD1CTL and LD2CTL and the lasers ON/OFF are controlled by LDC1 and LDC2 for CD and DVD, respectively. The following figure briefly describes the ALPC block. When the bit LDC1 is set low, the output voltage of LD0 will be pulled to VCC, hence the laser of CD will be turned off. Same manner is DVD laser control with LDC2 bit.

ALPC (Automatic laser plower control)

EFRFATN RFATN RFISEL

RFIGMSEL

GM VGA Equalizer

AGC

DPD

DVD/CD SW

direction

3BEAM TE

Central SERVO

Envelope Detector

RFOP

attenuator

RFON

HRFRP

DPFN

DPFO

TEO

FEO

CSO

(DVD)

DVDC

DVDB

DVDD

DVDA

CDFPI

CDFNI

TNI

TPI

RFGC

DVDRFIP

DVDRFIN

DVDD

DVDC

DVDB

DVDA

CDD

CDC

CDB

CDA

2. RF Amplifier Circuit

RF signal flow chart

2-1. INPUT STAGE

This block, including programmable attenuators and transconductors, is used for proper attenuation of input signals for different pick-up heads. Three input modes, defined by RFISEL are available for multiple inputs selection. Input mode also affects Gm, as definded by RFIGNSEL. The following table describes the relationship between input modes and selected Gm multiplicators. For example, if user chooses RFISEL =’10’(RFIN, RFIP) and RFIGMSEL =’11’( ), then effective GM is equal

to .4 = .

4∗K

1∗K

RFISEL1 RFISEL0 INPUT Multiplicator of Gm Input pins for DVD-ROM Input pins for CD-ROM

0 0 A,B,C,D

∗

1 DVDA,DVDB,DVDC,DVDD CDA,CDB,CDC,CDD

0 1 FEN FEP

∗

2 DVDRFIN, DVDRFIP CDC,CDD

1 0 RFIN RFIP

∗

4 DVDRFIN, DVDRFIP CDC, CDD

1 1 RFIN RFIP

∗

4 DVDRFIN, DVDRFIP CDC,CDD

For DVD_ROM mode, RF signal may be the sum of DVDA, DVDB, DVDC and DVDD which is also apply to DPD tracking error circuit. Furthermore, RF signal also can be obtained from pins DVDRFIN and DVDRFIP, which are the differential signals from OEIC, if the RF signal from OEIC is single-ended, it is all still available for mode ‘RFIN-RFIP’ by simply keeping DVDFIN floating. For CD_ROM mode, the differential RF inputs from OEIC may feed into pins CDC and CDD, which have the same function as DVDRFIN and DVDRFIP. It means that the function about ‘RFIN-RFIP’ mode in CD-ROM is the same as DVD_ROM except input pins being from CDC and CDD.

2-2. AGC (Automatic Gain Control) LOOP

AGC loop, as shown in Fig.1, is carried out for amplifying the RF signal from PDIC to a constant level at the output (RFON, RFOP). By controlling the gain of the GCA, the automatic gain control circuit holds the signal at the output (RFON, RFOP) at a constant level independent of the signal at GCA input. The GCA output signal level is determined by the DC voltage set on the pin RFGC. As the figure shown above, there are three AGC modes, defined by AGCMOD : AGC enable, RFGC DAC enable, and AGC hold. For ‘AGC enable’ mode, AGC loop is activated and user can apply different attack and decay bandwidth by programming IAGCDEC and IAGCATT respectively to optimize the system performance. For ‘RFGC DAC enable’ mode, a built in DAC, defined in RFGC], is utilized to perform the function of off-line AGC. Users can set the signal gain via programming the DAC after calculating the level of RFRP signal. For ‘AGC hold’ mode, RFGC pin becomes high impedance and the gain will keep almost at a constant level, even with low leakage current. Beside the AGC hold mode defined by AGCMOD, there is also a AGC hold function for defect protection. The destructive RF signal caused by defect may confuse the AGC function, one can hold AGC during this period by programming R[4].

2-3. EQUALIZER

This filter is intended to be used in the read channel of CD-ROM and DVD-ROM drivers with 8x constant linear velocity (CLV). As shown in following figure, the filter is placed in the automatic gain control (AGC) loop where it performs a dual role. It cuts off high frequency noise in the amplified read signal resulting in lower bit error rates.

For various operation speed, the filter cutoff frequency must be tunable over a wide range of about 3M45MHz. The second filter objective is to boost the high frequency component of RF signal which suffers from different MTF (modulation transfer function) from 14T to 3T. The equalizer uses two real zeros symmetric about the imaginary axis. The major requirement in the pulse equalizer design is phase linearity in the point of reducing intersymbol interference. In addition, the group delay must be independent of the amount of equalization to minimize jitter tolerance and be kept constant over 2*fc.

A tradition 7-pole 2-zero 0.05˚ equiripple type is determined for this filter design. In filter structure consideration, feedforward technique has been realized for its easy implementation instead of signal flow graph. Consequently, the control of cutoff frequency ƒcand boost gain can be easily accomplished in the second order section, included in this filter.

EFRFATN RFATN RFISEL

RFIGMSEL

Voltage DAC

Current DAC

comp

VGA Equalizer

Tracking

Top detector

Bottom Detector

DVDRF

Bottom Detector

RFOP

attenuator

RFON

HRFRP

CRTPLP

CRTP

LRFRP

DEFECT

RFGC

DVDRFIP

DVDRFIN

DVDD

DVDC

DVDB

DVDA

CDD

CDC

CDB

CDA

comp

Charge pump

Voltage DAC

RF signal flow chart

CDFPI

DVDFPI

1:CD

67k

134k

10k

FEON1

FELG (1Eh, b5)

10k

3~21.6k

FEG(1Eh,b4-0)

FEOS(0.8h,b4-0)

10k

67k

134k

10k

0:DVD

CDFNI

DVDFNI

IDACFE

FEO

33k

3. SERVO SIGNAL

3-1. FOCUSING ERROR

Block diagram is shown in following figure. the signal gain for focusing error is programmable by FEG. For

CD_RW and dual layer DVD_ROM applications, the amplitude of input signals are about one third of the one for normal CD_ROM and single layer DVD_ROM disk. Therefore, increasing the gain by three times, defined by FELG=0, is necessary for suitable gain range. In addition, the output voltage of FEO will suffer a offset voltage shift over normal operation range from semiconduction process. MT1326 provides a offset adjustment circuit comprising with FEOS. By programming IDACFE, it will generate an offset current flowing through external resistor R0, hence tuning the voltage of FEO back to the normal operation range. The offset voltage adjustment

is given as ∆V

offset

= -(I

DACFE

R0).

Focussing error

3-2. RF LEVEL (FLVL)

The signal FLVL which is the low-passed RF summing signal is used to indicate the focusing status for DVDROM mode, as shown in following figure. It also has the gain and offset programmability by LVLG and LVLOS, respectively.

CDFPI

DVDFPI

1:CD

54.5p

27.5p

67k

134k

10k~72k

32p

FLVLNI

FELG (1Eh, b5)

10k~72k

67k

134k

27.5p

54.5p

10k

0:DVD

CDFNI

DVDFNI

LVLG(1Fh, b4-0)

LVLS(09h, b4-0)

IDACFE

1: CD 0: DVD

FLVL

33k

SBAD

RF Level signal generator

CDCSPI

DVDCSPI

1:CD

54.5p

27.5p

67k

134k

10k

32p

CSON1

FELG (1Eh, b5)

10k

67k

134k

27.5p

54.5p

10k

0:DVD

CDCSNI

DVDCSNI

CSOS(0Ah, b4-0)

IDACFE

1 : CSO 0 : REO

CSO SEL (01h)

CSO

33k

TEO

3-3. CENTRAL SERVO

This signal is for central servo application. It is also a one beam push-pull tracking error signal. User can

select either CSO or TEO as the output signal through output pin CSO by programming ‘CSOSEL’.

CSO signal generator

TPI

1:CD

54.5p

27.5p

67k

35k

134k

TEG

3k~21.6K

10k

FLVLNI

TELG (21h, b5)

3k~21.6k

TEB(0Bh, b4-0)

8.4~15.2K

TEB(0Bh, b4-0)

8.4~15.2K

67k

35k

134k

27.5p

54.5p

16k

0:DVD

TNI

CSOS(0Ah, b4-0)

IDAC

FLVL

(SBAD)

33k

32k

SBAD

If select CD then FLVL output is SBAD

SABDOS (97h,b4-0)

3-4. SBAD (SUB_BEAM ADD)

The SBAD signal, the summing signal of both satellite PDs, is applied toward monitoring the focusing status for CD-ROM mode. The gain parameters setting for this signals is the same as 3-beam tracking error by TEGAIN. Offset cancellation DAC, defined SBADOS, is also required.

Sub beam Adder

TPI

1:CD

54.5p

27.5p

67k

134k

TEG 3k~21.6K

TEB (0Bh, b4-0)

8.4~15.2K

TELG (21h, b5)

3k~21.6k

11.8k

32k

33k

47P

32k

16k

11.8k

TEB(0Bk, b4-0)

8.4~15.2K

TEOS (06h,b5-0)

67k

35k

134k

27.5p

54.5p

0:DVD

1:CD 0:DVD

IDAC

35k

TNI

DPD

DVDA

DPFO

DPFN

TEO

DVDB DVDC DVDD

3-5. TRACKING ERROR

Two tracking error, 3-beam tracking error and DPD (differential phase detection), are available for CD_ROM and DVD_ROM, respectively. The block diagram is shown in following figure. For 3-beam tracking error, one can select different gain by TEGAIN, as well as adjust the gain ratio between these two satellite signals by TEBAL for unbalance compensation in satellite PDs. For DVD_ROM mode, the tracking error signals is switched to DPD automatically.

Tracking error

+ 33 hidden pages