LG CRN-8243B Service Manual

3

GENERAL FEATURE

SPECIFICATIONS

1. SUPPORTED SYSTEM

• IBM Compatible 486SX or Above

2. SUPPORTED OS

3. GENERAL PERFORMANCE

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

.............................................................................................10 Times Speed (Inner side) : 1,500 kbytes/sec

.............................................................................................24 Times Speed (Outer side): 3,600 kbytes/sec

• Data Buffer Capacity..........................................................................................1 Mbit DRAM (Internal DSP)

• Access Time ............................................................................................Random Access : Average 100 ms

4. POWER REQUIREMENTS

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

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

• Current .........................................................................................Peak in executing access : 1,000mA MAX

................................................................................................................................Random access : 800mA

..............................................................................................................................Normal operation : 600mA

..............................................................................................................................................Standby : 20mA

..................................................................................................................................................Sleep : 20mA

5. AUDIO PERFORMANCE

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

• S/N Ratio (IHF-A)..................................................................................................80 dB (Typical, 1KHz 0dB)

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

• Channel Separation ................................................................................................................65 dB (Typical)

• Dynamic Range (IHF-A)..........................................................................................................70 dB (Typical)

• Output Voltage (1kHz 0dB) 47kΩ Load.............................................................................0.78Vrms (Typical)

• Enhanced IDE interface

• Ultra Slim type CD-ROM drive

(Height: 12.7mm)

• Fast 110ms Average Access Time

• MAX 3,600KB/sec (24X) Sustained Transfer

rate

• Photo-CD Multisession Disc Spec compliant

• MPC level 3 Spec compliant

• Drawer Type Manual load/Electrical Release

• 3-Way eject support (Software, Open button,

Emergency eject)

• Built-in ATAPI Interface Controller

• Closed enclosure

• Software Volume Control

• 8 Times Digital Filter for CD Audio

• Built-in MODE-1 ECC/EDC

• MTBF 60,000h POH (at 10% Utilization)

• PIO Mode 4 & Multi-word DMA Mode 2

support & Ultra DMA Mode2 support

• Digital audio through ATAPI Interface

• Spin-down Mode for energy saving

• Support Standby & Sleep mode

• MS-DOS Version 3.1 or Windows 3.1

• OS/2 Warp (Ver 3.0 & 4.0) or higher

• Windows '95 or ‘98 higher

• Windows 2000

• Windows NT (Version 3.51 or 4.0) or higher

+1

-3

2. Trouble List (Circuit)

A. LED doesn’t light.
B. Pick-Up doesn’t move to the inner-track.
C. The Laser of Pick-Up doesn’t light.
D. Pick-Up lens doesn’t move up and down.
E. Disc doesn’t rotate.
F. TOC isn’t read. (The LED turns on, but doesn’t flicker.)
G. During Audio CD Play, LED flickers, but Speaker is silent.

20

TROUBLESHOOTING GUIDE

1. Initial Lead-in Operation

Reset or Power-On.

LED Flickers.

Pick-Up moves to the inner-Track.

Laser on the Pick-Up lights.

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

Focus Servo On (FEO(IC501 Pin 12 ) signal generation)

Rotate disc.

Tracking Servo On (TEO (IC501 Pin 15 ) Signal generation)

Spindle Servo On (DMSO(TP25) Signal generation)

Read TOC Area (LED Flickers)

Search the Start of Data Area and then pause.

21

3. Troubleshooting Guide

A. LED doesn’t light.

Check Power Voltage (TP1:3.3V, TP2:12V)
Reference Voltage

[TP5:V13(1.3V) and GND.]

Does “H” output in IC501 pin ?

Check and replace R705, R706, Q701
and LED701 (LED703 for DELL).

Is the CLOCK Frequency of
IC501 pin 33.86MHz?

Check the power input
pattern.

Check IC501.

Check and replace
X501; 33.86MHz.

Is the CLOCK Frequency of IC501 pin

33.86MHz?

Check and replace IC501.

YES

OK

NG

YES

YES

NO

NO

NO

37

54

54

A-1

A-1

22

B. Pick-Up doesn’t move to the inner track.

Do the signals appear at IC501
pin , ?
(Refer to Fig. B-1.)

Do the signals appear in PN301
pin?
(Refer to Fig. B-2.)

Does “H” output at IC201
pin ?

Is the 1.3V at IC201 pin ?

Check the pattern from
IC501 pin to IC201
pin

.

Check IC501.

Check IC501.

Check the PN301, and then
replace the Sled Motor.

YES

YES

YES

YES

NO

NO

Replace IC201.

NO

NO

173

41

25

174

165

41

CH1
PIN174
FMO

CH2
PIN173
FMO2

CH1 TP4

CH2 TP5

CH3 TP6

CH4 TP7

Fig. B-1. FMO and FMO2 Signals

Fig. B-2. TP4, TP5, TP6 and TP7 Signals

Check the pattern from
IC501 pin to R225
and then replace IC501.

23

Is the voltage of IC501 pin

(LD0) 1V?

Check Pick-Up FFC, PN101.

Check Q101, C101, C102
and then replace IC101.

YES

NO

10

181

Does the focus search signal
appear at F0S0 (TP9)?
(Refer to Fig. D-1.)

Is the 1.3V at IC201 pin ?

Check IC501.

YES

YES

YES

NO

NO

Replace IC201.

NO

25

Does the focus search signal
appear between F+ (TP10)
and F- (TP11)?
(Refer to Fig. D-2.)

C. The Laser of Pick-Up doesn’t light.

D. The Pick-UP lens doesn’t move up and down.

D-1

24

Check the pattern from
pin , of IC201 to
pin , of PN101.

Check the PN101, Pick-Up
FFC.

Replace the Pick-Up.

Replace PN101 or Pick-Up
FFC.

OK

OK

NG

34

35

1

4

CH1
TP9
(FAO)

CH1
TP10(F+)
TP11(F-)

Fig. D-1. F0S0 Signal

Fig. D-2. Focus Search Signal

D-1

25

Does the signal appear at
the DMS0 (TP25)?
(Refer to Fig. E-3.)

Do the signals appear at
IC201 pin (W), (V),
and (U)?

Replace IC501.

Replace IC201.

YES

NO

NO

12

14

13

Check the pattern from
IC201 pin , , to
PN201 , , .

YES

OK

12

13

14

13

12

11

Check Spindle Motor FFC

and then replace the

Spindle Motor.

Does the signal appear at
FEO(IC501 pin ) when
the R126 opened?
(Refer to Fig. E-1.)

YES

YES

YES

NO

NO

Replace IC501.

Replace IC501.

Replace Pick-Up.

NO

Do the signal appear at
FEO (IC501 pin )?
(Refer to Fig. E-2.)

Does the signal appear at
F+(TP10) during focus
search?

E. Disc doesn’t rotate.

12

12