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This service manual provides a variety of service
It contains the mechanical structure of the CD-
R/RW Drive and the electronic circuits in
schematic form. This CD-R/RW Drive was
manufactured and assembled under our strict
quality control standards and meets or exceeds
industry specifications and standards.
This CD-R/RW drive is an internal drive unit
designed for use with IBM PC, HP Vectra, or
1. General
1) Enhanced IDE interface.
2) Internal 5.25 inch, halfheight CD-R/RW Drive.
3) 2 Mbytes buffer memory.
4) Audio CD like tray loading of a disc without using a caddy.
5) Power loading and power ejecting of a disc. The disc can also be ejected manually.
6) Supports Power saving mode and Sleep mode.
7) Vertical and Horizontal operation.
2. Supported disc formats
1) Reads and writes data in each CD-ROM, CD-ROMXA, CD-I FMV, Video CD, and CD-EXTRA
2) Reads data in Photo CD (Single and Multi session).
3) Reads and writes standard CD-DA.
4) Reads and writes CD-R discs conforming to "Orange Book Part 2".
5) Reads and writes CD-RW discs conforming to "Orange Book Parts 3".
3. Supported write method
1) Disc at once (DAO), Session at once (SAO), Track at once (TAO), Variable packet, Fixed packet, and
4. Performance
1) Random 100 ms average access time.
2) Max 4,800 kB/sec (Max 32X) Sustained Transfer rate.
3) Supports real time error correction and real time layered error correction at each speed.
4) Supports CD-R write operation at double speed, quadruple speed, and eight speed.
5) Supports CD-RW write operation at double speed and quadruple speed.
6) PIO Mode 4 & Multi DMA Mode 2 Support.
7) MPC-3 Spec compliant.
5. Audio
1) Output 16 bit digital data over ATA interface.
2) 4 Times Digital Filter for CD Audio
3) Software Volume Control
4) Equipped with audio line output and headphone jack for audio CD playback.
5) Front panel Volume Control for Headphone Output.
compatible computer. It can write as much as 650
Mbytes of digital data into CD-R/RW disc, and can
read as much as 650 Mbytes of digital data stored
in a CD-ROM, CD-R and CD-RW disc.
This CD-R/RW Drive can easily meet the
upcoming MPC level 3 specification, and its
Enhanced Intelligent Device Electronics (E-IDE)
and ATAPI interface allows Plug and play
integration in the majority of today's PCs without
the need of an additional interface card.


   Related Manuals for LG CED-8081B

   Summary of Contents for LG CED-8081B

  • Page 1

    INTRODUCTION compatible computer. It can write as much as 650 This service manual provides a variety of service Mbytes of digital data into CD-R/RW disc, and can information. read as much as 650 Mbytes of digital data stored It contains the mechanical structure of the CD- in a CD-ROM, CD-R and CD-RW disc.

  • Page 2: Specifications

    SPECIFICATIONS 1. SYSTEM REQUIREMENTS -CPU: IBM Compatible Pentium 233MHZ (or faster) (For 8X Write speed, 266MHz or faster recommended.) -32MB Memory or greater 2. SUPPORTING OPERATING SYSTEM • DOS 3.1 or Higher • Solaris Ver 2.4 or higher • Windows ‘95/’98/’2000 •...

  • Page 3

    1KHz 0dB No Filter H/P Volume MAX Output Level * CED-8081B FUNCTION TABLE M M O O D D E E L L F F u u n n t t i i o o n n C C E E D D - - 8 8 0 0 8 8 1 1 B B •...

  • Page 4: Location Of Customer Controls

    LOCATION OF CUSTOMER CONTROLS Front Panel Emergency Ejct Hole Disc Tray Stop/Eject Button Play/Skip Button Volume Control Drive Activity Indicators Headphone Jack 1. Disc tray 5. Volume control This is the tray for the disc. Place the disc on the This is used to adjust the output volume of the ejected disc tray, then lightly push the tray (or headphone jack.

  • Page 5: Rear Panel

    Rear Panel Analog Audio Output Connector IDE Interface Connector Jumper Connector Power Connector Digital Audio Output Connector 1. Power Connector 3. Jumper Connector Connects to the power supply (5-and 12-V DC) of This jumper determines whether the drive is the host computer. configured as a master or slave.

  • Page 6

    DISASSEMBLY 1. CABINET and CIRCUIT BOARD 1-3. Cabinet and Main Circuit Board A. Remove the Cabinet in the direction of arrow (4). DISASSEMBLY (See Fig. 1-3) 1-1. Bottom Chassis B. Release 2 hooks (a) and remove the CD Tray A. Release 4 screws (A) and remove the Bottom Chassis drawing forward.

  • Page 7

    2-2. Pick-up A. Release 1 screw (C) and remove the Pick-up. Pick-up Unit Pick-up Fig. 1-5 2-3. Sled Motor Assy A. Release 2 screws (D),(E) and remove the Sled Motor Assy. Sled Motor Assy (D) (E) Fig. 1-6...

  • Page 8: Troubleshooting Guide

    TROUBLESHOOTING GUIDE Reset or Power Check. Check it after connecting the power cable only on interface cable for NO Reset or Power ON. Are the pin 41 • Check the power(12V, 5V) short. and 44 of PN201 +12V and +5V •...

  • Page 9

    System Check. Load tray without inserting disc. Does Tray operate normally? Go to “Tray operating is abnormal” Go to “Sled operating is abnormal” Does Pick-up move to inside? Does Spindle Motor Go to “Spindle operating is rotate in a moment? abnormal”...

  • Page 10

    Tray operating is abnormal. (Tray open/close doesn’t work) Is the input voltage • Check the connection of IC301 pin 10. 0V at IC301 pin 10 when push the • Replace the SW802(Eject s/w) SW802? • Check the connection of IC409 pin 12. •...

  • Page 11

    Sled operating is abnormal. Is there Sled Check the communication line Replace the IC409. control signal output? between IC409 and IC301. (IC409 pin 7) Is there Sled drive voltage • Check the connction of IC502 pin 17. input? (IC501 pin 23) •...

  • Page 12

    Spindle operating is abnormal Is there Is there • Check the connection of IC201 pin 2. DMO signal input? Spindle control signal input? • Replace the IC201(OTI-9790). (IC509 pin 5) (IC510 pin 22) Is there Spindle • Replace the IC509(NJM3404). control signal output? (IC509 pin 7) Replace the IC508(BU4053).

  • Page 13

    Focus Actuator operating is abnormal • Check the connection of IC201 pin 207. Is there Focus • Check the communication line between Search control signal input? IC201 and IC301. (IC501 pin 3) • Replace the IC201 (OTI-9790) • Is there Focus Check the connection of IC301 pin Is Act_Mute signal “L”? Search drive voltage output?

  • Page 14

    Spindle control is abnormal 2 (CD-ROM Disc) Is there RRF signal input? Go to “RF output is abnormal” (IC403 pin 3, 2) Is there EFM signal output? Replace the IC403(KM4200). (IC403 pin 7) Does Tracking Servo Go to “Track Servo is unstable” operate normally? Go to “Disc recognition is abnormal”...

  • Page 15

    Disc recognition is abnormal Is there RECD1, Is there CDR/RW signal input RECD2 signal output normally? Go to “RF output is abnormal” normally? (IC601 pin 33) (IC401 pin 61, 62) Go to “Track Servo is unstable” Replace IC301 (MICOM) RF output is abnormal Is there PICK UP (A, B, C, D) •...

  • Page 16

    Focus Servo is unstable Is FE signal output normal in Focusing Check the IC401(OTI9071). Up/Down? (IC401 pin 30) Go to “RF output is abnormal” Is FAQ signal output normal in Focusing Replace the IC201(OTI-9790) Up/Down? (IC201 pin 207) Go to “Focus Actuator operating is abnormal”...

  • Page 17

    Laser is abnormal Execute ‘B.Calibration Data’ of ‘How to use Test Tool (Dragon)’ Is EEPROM Data valid? Execute ‘D.LD Inspection’ of ‘How Execute ‘C.LD Power Setup’ of to use Test Tool(Dragon)’ ‘How to use Test Tool(Dragon)’ OFF LEVEL NG? Normal VRDC NG? VWDC1 NG?

  • Page 18

    2.4+/-0.3V? • Check the connection of IC401 pin 12. PN401 Pin 25(VRDC) : • CED-8081B:0.9 + 0.5V? Check and replace the IC401. Execute ‘D. LD Inspection’ of ‘How to use Test Tool(Dragon)’ VRDC NG? Check the P/U connector and then Normal replace the P/U.

  • Page 19

    LD CHECK (Not Recorded) Execute ‘E. LD On’ of ‘How to use Test Tool(Dragon)’: ‘VWDC-1 Loop’ • Check the connector of IC601 pin 20. PN401 Pin 32(ENAB) = ‘H’? • Check and replace the IC601(Asic). • Check the connection of IC601 pin 18,29 and 34. PN401 Pin 31(W/XR) = ‘H’? •...

  • Page 20

    PN401 Pin 31(W/XR) = ‘H’? • Check and replace the IC601(Asic). • Check the connection of IC409 pin 19. PN401 Pin 26(VWDC2) : • CED-8081B:3.4 + 0.4V? Check and replace the IC409(DAC). Check the P/U connector and replace the P/U.

  • Page 21

    Does the disc if the disc has long width have any Dust, Scratch, Scratch, change it. Fingerprint...? Use LG bundle Software (Write Tool & Version) Is the write Tool(version) - Easy CD Creator 4.02c supported by LG CD-RW Direct CD 3.01c...

  • Page 22

    Writing Part Check. Refer “Laser is abnormal”. Load tray with CD-R/RW Disc. Run the Writing Tool (Easy CD Creator). Run the Writing with Tool (Easy CD Creator). The blink Do the IC301(MICOM) alternates between LED1 and pin 11 and pin 12 output toggle LED2 when Writing start (OPC signals during Writing? operation)?

  • Page 23

    ALPC Logic Circuit Check. Execute ‘E. LD On’ of ‘How to use Test Tool(Dragon)’ : ‘CD-R Recording Mode’ • Check the connection of IC301 pin 23. IC601 Pin 33 (CDR/RW) = ‘H’? • Check and replace the IC301. • Check the connection of IC301 pin 20. IC601 Pin 34(WR/RE) = ‘H’? •...

  • Page 24

    Execute ‘E. LD On’ of ‘How to use Test Tool (Dragon)’ : ‘CD-RW Recording Mode’ • Check the connection of IC301 pin 23. IC601 Pin 33(CDR/RW): ‘L’? • Check and replace the IC301. • Check the connection of IC301 pin 20. IC601 Pin 34 (WR/RE) : ‘H’? •...

  • Page 25

    BETA Measurement Circuit Check. After inserting Test Disc (TCD-784), 1x play. • Check the connection of IC401 pin 89. IC401 Pin 89(RRF) : 2.5V+/-1.0V? • Check and replace the IC401(OTI9071). • Check and replace the IC301 (MICOM). IC301 Pin 23(CDR/RW) : ‘H’? •...

  • Page 26

    No audio output Insert the audio Disc. AUD_MUTE : ‘L’? • Check and replace the IC301. (IC301 Pin 6) Do LOUT, ROUT signals output? • Check and replace the IC201. (IC201 Pin 151, 154) Do audio Line signals output? • Check the connection of L/R OUT.

  • Page 27

    In case of audio play switch not working. • Check the connection of IC301 pin8. Is IC301 pin 8 5V before pushing • Replace the IC301. PLAY KEY (SW801)? • Check the connection of SW801. Is IC301 Pin 8 0V pushing the •...

  • Page 28

    GLOSSARY ATIP Absolute Time in Pre-groove. With an additional modulation of the “Wobble”, the “Groove” contains a time code information. Wobble The pre-groove in the Disc is not a perfect spiral but is wobbled. With : – A typical amplitude of 30 nm –...

  • Page 29: Recording Layer

    The differences of CD-R/CD-RW discs and General CD-ROM 1. Recording Layer Recordable CD has a wobbled pre-groove on the surface of disc for laser beam to follow track. Track pitch(p) a=30nm Read-only Disc CD-ROM (READ-ONLY DISC) Radial Direction Radial Error Signal 0.4~0.5 um Groove Land...

  • Page 30: Disc Materials

    3. Disc Materials 1) CD-ROM disc • It is composed of Silver _ colored aluminum plate and Reflective layer. • Groove (Pit) of aluminum plate make a track. • Laser wavelength : 780 nm, Laser Power (Read): 0.5mW • Signal is detected by the difference of reflective beam intensity between “pit”...

  • Page 31: Reading Process Of Optical Disc

    3 3 ) ) C C D D - - R R W W D D i i s s c c Label Printing Protective Layer Dielectric Layer(TL) Reflective Layer Dielectric Layer(UL) Substrate (Polycarbonate) Groove Laser Beam • It is composed of polycarbonate layer, alloy(silver, arsenic) layer, aluminum reflectivity layer, protective layer. •...

  • Page 32

    5. Writing Process of CD-R Disc Incident (Write) Laser Power (Read) (Read) Laser Spot a b c d e f Position (Time) Laser Below "ORP"– Mark Too Short Spot Reflected At Optimum Record Power ("ORP") Light Signal Above "ORP" – Mark Too Long Recorded Mark Time...

  • Page 33

    7. Organization of the PCA, PMA and Lead-in Area 1) Layout of CD-ROM disc Disc Center Diameter 120 mm Diameter 46 mm Diameter 15 mm Center hole Clamping and Label Area Information Area Read Only Disc Lead-in Area Program Area Lead-out Area 2) Layout of CD-R/RW disc Disc Center...

  • Page 34: Function Of Pca And Pma Area

    8. Function of PCA and PMA area 1) PCA (Power Calibration Area) • PCA area is used to determine the correct Laser Power for a disc. – Method 1 : PCA area is divided by a track. – Method 2 : The previous Calibration value is referred. –...

  • Page 35: Writing Process Of Disc

    2) ROPC (Running Optimum Power Control) • Variable primary factor of Optimum Power – Change of Power sensitivity on the Disc. (limited to 0.05 *Po) – Wavelength shift of the laser diode due to the operating temperature change. – Change of the Spot aberration due to the Disc skew, Substrate thickness, Defocus.

  • Page 36

    INTERNAL STRUCTURE OF THE PICK-UP 1. Connection diagram of the Pick-up *KRS-202A : CED-8081B¡fl S 2 Axis Actuator FCS - TRK - TRK + FCS + FGND PDGND PDVcc PDVc FPDVc FPDO CFREQ CMOD PGND VRDC Q1 S VWDC2 VWDC1...

  • Page 37

    2. Pin Description Pin No. Symbol Function FCS- Focus coil- TRK- Tracking coil- TRK+ Tracking coil + FCS+ Focus coil + FGND Frame GND PGND PDIC GND PDIC F OUT PDIC B OUT PDIC A OUT PDIC H OUT PDIC VCC PDIC VC PDIC G OUT PDIC D OUT...

  • Page 38

    3. Signal detection of the P/U Infrared Iaser Pick-Up module Focusing Tracking Photo Diode 1) Focus Error Signal ==> (A+C)-(B+D) This signal is generated in RF IC (IC401 : CXA2551R) and controls the pick-up’s up and down to focus on Disc.

  • Page 39: Description Of Circuit

    DESCRIPTION OF CIRCUIT 1. ALPC (Automatic Laser Power Control) Circuit 1-1. ALPC Loop Circuit IC409 (BU2500FV)

  • Page 40

    1-2. ALPC(Automatic Laser Power Control) Circuit Operation This circuit consists of Feedback Loop to maintain light output of the Laser Diode (FPDO). Feedback signal, output voltage from PD (Photo Detector) of P/U, is used monitor the light power of Laser Diode.

  • Page 41

    2. RF Amplifier Circuit Block Diagram...

  • Page 42

    3. Focus/Tracking/Sled Servo Circuit 3-1. Focus, Tracking & Sled Servo Process Focus, Tracking Serve IC401 OTI9071 Pick up A,B,C,D,E,F,G,H A,B,C,D Focus Error Detector A,B,C,D Track Error Detector E,F,G,H Focus, Tracking Actuator IC201 IC501 Servo control Driver OTI9790 BA5983FM Level shift Digital EQ Auto Adj.

  • Page 43

    3-2. Focus Servo The aim of Focus Servo is to maintain the distance between object lens of P/U and disc surface, so that the detected RF signals (A, B, C, D) can be maximized. Focus Servo is based on focus error (FE) signal which is generated from focus error detection block in OTI9071 (IC401) using Astigmatism Method.

  • Page 44: Spindle Servo Circuit

    4. Spindle Servo Circuit 4-1. Spindle Servo Process Pick up IC401 OTI9071A WBLIN Wobble Signal Generator Spindle Motor IC201 OTI9790 Hall sensor IC510 BA6664FM CD-DSP/SERVO CD EFM CLV IC508 CAV x32 Decode PLL BU4053 Frequency Controller LOCK SPN8/12Cm FILTER SPNBOOST DEFS MOTOR SPEED ATIP CLV, FG...

  • Page 45: Major Ic Internal Block Diagram And Pin Description


  • Page 46

    • Pin Assignment Pin No. Name Analog Digital Pin Description Type Type AVDD Analog power FPDI Laser power monitor output FVREF APC reference voltage FPDO Laser power monitor output WREF Power setting input/output voltage for write APC VWDC Laser driver control output for write. VWDC1 Auxiliary laser driver control output for write.

  • Page 47

    Pin No. Name Analog Digital Pin Description Type Type Track crossing signal DVDD Digital power Zero crossing of TE DVSS Digital ground Zero crossing of RP WPLTSH SWRF1 sample gate WREFSH SWRF2 sample gate RFPDSH Sample pulse for read APC WFPDSH Sample pulse for write APC MPDSH...

  • Page 48

    Pin No. Name Analog Digital Pin Description Type Type RRFIN1 RRF input pin for peak/bottom hold 1 RECDIN RF input for recording area detection AVDD Analog power Read RF signal output AVSS Analog ground Main beam input signal (A) Main beam input signal (B) Main beam input signal (C) Main beam input signal (D) HAVC...

  • Page 49

    IC201(OTI-9790) : ATAPI Interface, Write and DSP Signal Processor Block Diagram RD[15:0] DPLL OTI-9790 ROE# VPSET CIRC RCASL# Register RCASH# MONIT DRAM RWE# DEFS EFMR3 Interface EFMR2 RRAS0# Subcode DSFS Decoder 4K SRAM EFMR1 RA11/RRAS1# Interface SUBIN RA10/RRAS2# SUBCK RA9/RRAS3# PANICIN ESFS CIRC...

  • Page 50

    • Pin Description Clock Pin No. Pin Name Type Description Crystal In : System Clock (33.8688MHz) XOUT Crystal Out: System Clock CLKOUT Clock Output C34M Set to 34.5744MHz CD ENCODER/DECODER Interface Description P P i i n n N N o o . . P P i i n n N N a a m m e e T T y y p p e e PANICIN...

  • Page 51

    CD-SERVO Interface Pin No. Pin Name Type Description Spindle Motor Servo Output Sled Servo Output Focus Servo Output : Focus servo feedback signal Tracking Servo Output : Tracking servo feedback signal TEBC Tracking Error Balance Control Focus Error Tracking Error Beam Strength : This input from the preamplifier is the sum of the E and F photodiode outputs when using a 3-beam pick-up RPBC...

  • Page 52

    AUDIO Interface Pin No. Pin Name Type Description MIO0 Multi Purpose I/O MIO1 Multi Purpose I/O MIO2 Multi Purpose I/O DOUT Digital Audio Output : Bi-phase serial audio output that follows the EIAJ CP1201 standard. MIO3 Multi Purpose I/O Left Channel Audio Output Right Channel Audio Output Note: MIO3-0 can be programmed to control an external audio DAC.

  • Page 53

    Pin No. Pin Name Type Description DMACK# ATA DMA Acknowledge/DMA Request : ATAPI DMA acknowledge DMA request when connected to SCSI controller IORDY/ DDMARDY#/ ATA Host I/O Ready : I/O channel ready DSTROBE UDMA : DDMARDY#, device DMA ready; DSTROBE, device data strobe HRD#/ HDMARDY#/ ATA Host Read Strobe/SCSI DMA Read Strobe...

  • Page 54

    Pin No. Pin Name Type Description Address : Use these pins if the microcontroller has a separate address and data bus. UA15 UA14 UA13 UA12 Address : Use these pins when accessing 64 KB buffer memory window. UA11 UA10 UALE Address Latch Enable : Use this pin if the microcontroller has multiplexed addess and data bus.

  • Page 55

    Pin No. Pin Name Type Description RAM Data : Data for DRAM Possible to set bus size (16 bit/8bit) by setting internal registers RRAS0# Row Address Strobe 0 : RAS for DRAM RCASH# Column Address Strobe High : CAS0 for DRAM – If 16 bit bus is selected, this pin used by strobe RCASL# Column Address Strobe Low...

  • Page 56

    IC301 (MB90F476) : MICOM Block Diagram Clock control X0, X1 RSTX circuit F MC-16LX family Core X0, X1A Interrupt controller PPG0, 1 8-/16-bit PPG PPG2, 3 PPG4, 5 µDMA AIN0, 1 8-/16-bit UD counter BIN0, 1 Communication prescaler ZIN0, 1 SIN0 UART SOT0...

  • Page 57

    •Pin Description Port Name Assign Description P22/A18 pSLnMA Master/Slave detection input P23/A19 pnOpenSW Open switch input P24/A20/PPG0 P25/A21/PPG1 P26/A22/PPG2 pnLoadSW Load switch input P27/A23/PPG3 pAudMute Audio mute output P30/A00/AIN0 pXTOR Tracking error amplitude detection input P31/A01/BIN0 pnPlayKey Play key input GND_ P32/A02/ZIN0 pnEjectKey...

  • Page 58

    Port Name Assign Description P83/IRQ3 pATIPnEFM Atip/EFM select output P84/IRQ4 pPRST OTI9790/OTI9071 Reset control output P85/IRQ5 pnSDInt OTI9790 Servo interrupt input P86/IRQ6 pUint1 OTI9790 Interrupt 0 input P87/IRQ7 pUint0 OTI9790 Interrupt 1 input P90/SIN1/CS0 pnUCS1 OTI9790 Register select1 P91/SOT1/CS1 pnUCS0 OTI9790 Register select2 P92/SCK1/CS2 P93/FRCK/ADTG...

  • Page 59

    IC409(BU2500FV) 1) The BU2500FV is an integrated circuit semiconductor of CMOS structure with 12 channels of built-in D-A converters with output buffer operational amplifiers. 2) Outputs of 12 channels are used for adjustment/control of servo circuits and references. Block Diagram Ao12 Ao11 12-BIT SHIFT REGISTER...

  • Page 60

    IC501 (BA5983 FM) 1) It controls the sled movement in track search mode and takes the tray to open/close. 2) It controls the Focus/Tracking Actuator receiving the focus error or tracking error signal from IC201. Block Diagram Standby 10K 10K LEVEL SHIFT LEVEL...

  • Page 61

    IC510 (BA6664FM) : Spindle Motor Drive IC It drives the spindle motor receiving the spindle control signal at IC301 (MICOM) and IC201 (OTI-9790). DRIVER Block Diagram GAIN GAIN SWITCH CONTROL CURRENT SENSE AMP HALL AMP TORQUE SENSE AMP SERVO SIGNAL Hall 1 H2 + CK Q...

  • Page 62

    IC502 (BA5925FV) It detects the speed of the moving sled, and transfers the sled control signal from IC201 (OTI-9790) to IC501 (BA5983FM) Block Diagram 6.8K EDGE LEVEL SHIFT LOGIC 100K 100K 100K 100K STBY 8.2K 8.2K 8.2K 8.2K • Pin Description Pin No.

  • Page 63


  • Page 64

    2. Power Block Diagram...

  • Page 65

    3. Control Signal Block Diagram...

  • Page 66

    4. Read/Write Signal Block Diagram...

  • Page 67

    5. Block Diagram * CED-8081B : Optical Pick-up KRS-202A 33.86MHz cable OTI9790 OTI9071 DSP + Servo RF Amp. DECODER Wobble ENCODER ALPC ATIP Demodulator Data Write Strategy *Optical DRAM Disc Pick-up Motor unit KRS-202A GRS-R02A/ Data Laser OSM-32A Control Asic...

  • Page 68


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