LG CRD-8161B Service Manual

INTRODUCTION

GENERAL FEATURE

SPECIFICATIONS

1. SUPPORTED SYSTEM

IBM Compatible 486SX or Above

2. SUPPORTED OS

3. GENERAL PERFORMANCE

• Data Transfer Rate..........................................................................................Sustained Data Transfer Rate

Normal Speed : 150 kbytes/sec

16 Times Speed(max) : 2,400 kbytes/sec

• Data Buffer Capacity .....................................................................................................................128 kbytes

• Access Time......................................................................................................1/3 Stroke Average : 100 ms

4. POWER REQUIREMENTS

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

+12V DC+5%

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

+12V : 100mVp-p

• Current ...........................................................................................+12V : 150mA (Average), 1A (Maximum)

+5V : 400mA (Average), 0.6A (Maximum)

5. AUDIO PERFORMANCE

• Frequency Response....................................................................................................100Hz~20KHz(+3dB)

• S/N Ratio (IHF-A)..............................................................................................85 dB (Typical at 1 KHz 0dB)

80 dB (Limit at 1 KHz 0dB)

• T.H.D. (20K-LPF) .............................................................................................0.05% (Typical at 1 KHz 0dB)

0.15% (Limit at 1 KHz 0dB)

• Channel Separation .................................................................................................................80 dB(Typical)

70 dB(Limit)

• Output Voltage (1kHz 0dB) 47KΩ Load ................................................................................0.7 Vrms + 20%

• Enhanced IDE interface

• Internal 5.25 inch, halfheight CD-ROM Drive

• Fast 100ms Average Access Time

• Supports 1X and 16X Rotational Modes

• Max 2,400KB/sec Sustained Transfer rate

• Photo-CD Multisession Disc Spec compliant

• Multimedia MPC-3 Spec compliant

• Power Disc Loading/Ejection Mechanism

• 1 Way Eject support (Eject Button )

• Closed Enclosure

• Built-in ATAPI Interface Controller

• Software Volume Control

• 4 Times Digital Filter for CD Audio

• Built-in MODE-1 ECC/EDC

• MTBF 125,000h POH (at 10% Utilization)

• PIO Mode 4 & Multi DMA Mode 2 support

• Horizontal or Vertical Mounting

• Digital audio output

• Digital audio through ATAPI Interface

• Subcode (P-W) through ATAPI Interface

• Spin-down Mode for energy saving

• MS-DOS Version 3.1 or Higher

• OS/2 Warp (Ver 3.0)

• Windows '95

• Solaris Ver 2.4 or Higher

• Linux slackware 2.3

This service manual provides a variety of service information. It contains the mechanical structure of the CD-ROM Drive together with mechanical adjustments and the electronic circuits in schematic

form. This CD-ROM Drive was manufactured and assembled under our strict quality control standards and meets or exceeds industry specifications and standards.

LOCATION OF CUSTOMER CONTROLS

FRONT VIEW

1. Headphone Jack

3.5mm jack for monitoring the audio signal from audio CDs.

2. Headphone Volume Control

Adjusts the headphone sound level.

3. Disc Slot

Push a 12cm CD-ROM disc into slot.

4. Busy Indicator

The Busy Indicator lights during initialization and dataread operations.

5. Play/Skip Button

When an Audio CD is in the unit, pressing this button will start playing audio CDs from the first track. If an audio CD is playing, pressing this button will skip to the next track.

6. STOP/EJECT Button

This button is pressed to eject the CD disc. The button works only when power is applied to the drive. If an audio CD is playing, pressing this button will stop it, and pressing it

again will eject the CD disc.

Figure 1. Front View

2 54 6

BACK VIEW

1. Digital Audio Ouput Connector

This is a digital audio output connector or Video CD output connector. You can connect this to the digital audio system or Video CD Board.

2. Analog Audio Output Connector

The Audio Output Connector connects to a sound card. The supplied audio cable is a SoundBlaster

type cable. If you have a different sound card, you must optain the proper for that card.

3. Master / Slave / CSEL Jumper

These three jumpers are used to set the CD-ROM Drive to either a Master, Slave, or CSEL drive.

4. Interface Connector

This 40-pin connector is used to transfer and control signals between the CD-ROM Drive and your PC. Connect the 40-pin IDE cable in your PC to this connector.

5. Power-in Connector

Attach a power cable from the computer to this connector.

Figure 2. Back View

DIGITAL ANALOG

INTERFACE POWER

DR CSM

SLA

GLG39 1

+12

GND

40 2

AUDIO AUDIO

FRONT

REAR

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. Release 4 stoppers and remove the Front Bezel

Assy.

1-3. Top Case and Chassis Mecha

A. Release 2 hooks (a) and remove the Top Case in

the direction of arrow (2).

B. Release 4 screws (B) and remove the Chassis

Mecha in the direction of arrow (3)

1-4. Main Circuit Board.

A. Remove the Main Circuit Board in the direction of

arrow (4).

B. At this time, be careful not to damage the 4

connectors of the Main Circuit Board.

Bottom Chassis

(1)

(A)

Fig. 1-1

Chassis

Mecha

Top Case

Hooks (a)

(B)

(2)

(3)

(B)

Fig. 1-3

Main

Circuit Board

4 Connectors

(4)

Fig. 1-4

Front Bezel Assy

Stoppers

Fig. 1-2

DISASSEMBLY

2. MECHANISM ASSY

2-1. Pick-Up Unit

A. Release 1 screw (C). B. Remove the Loading Belt and Loading Gear. C. Release 1 screw (D). D. Remove the stopper (R). E. Release 1 screw (E). F. Remove the Elevator Cover. G. Release 2 screws (F). H. Remove the Pick-Up Unit in the direction of

arrow (5).

* NOTE

When reassembling the Timing Gear and the Elevator gear, align the mark( ) of Timing Gear with the mark(o) of Elevator Gear.

2-2. Pick-Up

A. Release 1 screw (G). B. Remove the Pick-Up

Mechanism

Assy

Stopper(R)

Pick-UP

Unit

Elevator Gear

Gear

Elevator Cover

Timing Gear

Loading Belt

(E)

(C)

(F)

(D)

(5)

Fig. 2-1

Pick-Up

Unit

Pick-Up

(G)

Fig. 2-2

TROUBLESHOOTING GUIDE

1. Initial Lead-in Operation

Reset or Power-On.

LED Flikers.

Pick-Up moves to the inner-Track.

Ratate disc.

Laser on the Pick-Up lights.

Focus Search (through moving up and down the lens of Pick-Up)

Focus Servo On (FOK(TP10) : H, FEO(TP14) signal generation)

Tracking Servo On (TEO(TP13) Signal generation)

Spindle Servo On (MDP(TP17) Signal generation)

Read TOC Area (LED Flikers)

Search the Start of Data Area (00:02:16) and then pause.

2. Trouble List (Circuit)

(In the Initial Lead-in Operation Mode)

A. LED doesn’t light. B. Pick-Up doesn’t move to the inner-track. C. Disc doesn’t rotate. D. The Laser (RED) of Pick-Up doesn’t light. E. Pick-Up lens doesn’t move up and down. F. TOC isn’t read. (The state LED is not disappear.)

(In the Operation Mode)

G. Jump is unstable (Noises are occurred.) H. During the Access, Pick-Up slides innermost track or outermost track. I. High speed operating (8~16 times) is performed, but normal speed (1 time: Audio CD) operating is

unstable. J. During Audio CD Play, LED flickers, but Speaker is silent. K. Trouble for compatibility.

3. Troubleshooting Guide (In the Initial Lead-in Operation Mode)

Reset or Power On.

Check Power Voltage, Reference Electrical Potential and GND.

Does LED light?

Does Pick-Up move to the inner track?

Does “H” output in IC401 pin ?

Is the CLOCK Frequency of X401 16.93MHz?

Check and replace R318, R323, Q307 and LD301.

Does the signal appear in the IC401 pin , ?

Replace IC401

Does Disc rotate?

Does the signal appear in the FOK(TP10), IC501 pin ?

Replace IC501

Replace IC201

Does the signal appear in the TP1, TP2?

Replace IC203

Replace MD Assy.

(Sled Motor is defective.)

Replace X401.

YES

YES YES

YES

NO NO NO

106

Dose the signal appear in the MDP(TP17), IC501 pin ?

Does the signal appear in IC203 pin (A3),

(A2) and (A1)?

Replace MD Assy.

Does the signal appear in IC501 pin ?

FEO

SENS

115

Does the Laser (RED

light) of Pick-Up light?

Does “H” output in IC102 pin ?

Replace IC401

YES

YES YES

YES

Does the Pick-Up lens

move up and down?

Does the focus search signal appear between pin and of IC203?

Replace IC203

NONO

Is the Focus Servo On?

(Does FEO(TP14) signal

appear?)

Is the Voltage of IC102 pin (LD) 2.2V?

Replace IC102

Replace MD Assy

(Laser Diode of the

Pick-Up is defective.)

Replace MD Assy

(Focus actuater coil of the

Pick-Up is defective.)

Focus Servo is unstable

Is the Tracking Servo

On? (Does TEO(TP13)

signal appear?)

Tracking Servo is

unstable

Replace IC501,

MD Assy or Main Circut

Board.

Is the Spindle Servo On?

(Does MDP(TP17) Signal

appear?)

Spindle Servo is unstable.

Is TOC area on the Disc read? (Does LED flicker?)

NO NO

Does the other Disc

operate normally?

Disc is defective.

The End.

Replace Main circuit

Board or MD Assy.

4. Troubleshooting Guide (In the Operation Mode)

When the jump is unstable (Noise occurs);

(1) Readjust the Slide Motor offset.

(2) Replace Main Circuit Board or MD Assy.

When the Pick-Up slides to innermost track or outermost track during the Access;

(1) Replace MD Assy.

When the High Speed operating (8~16 times) is performed, but normal speed operating (1 time) for

Audio CD is unstable;

(1) Perform Down Load again.

(Refer to Owner’s Manual)

(2) Replace MD Assy.

During Audio CD play, LED flickers, but Speaker is silent;

When the headphon volume is not controlled;

(1) Replace VR301

Others (Video CD is not played, screen is abnormal or some title is not played.)

: Troubles for Compatibility

5. When the data read failure of CD-ROM Disc

(1) Check the CD-ROM Disc. (2) Check the IC's in the decoder and interface circuit.

a) DRAM : IC601 b) CD-ROM Decoder & E-IDE Controller : IC602 c) Microprocessor : IC401

J-1

Does PWM signal appear in IC501 pin ?

Replace IC501.

YES

83,91,92

Does Audio signal appear in IC301 pin ?

Replace IC301.

YES

Are L-CH and R-CH

signals appeared in

JK301 and JK302 each?

Replace L310, L311.

YES

Is the connection between JK301(or JK302) and Line

(or Jack) normal?

Normal.

Speaker is defective.

YES

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