Dell GCR-8481B Service Manual Download

Page: 22 / 24

Pin No.

Symbol

I/O

COMMENT

153

HDBA

I/O

1,Z,0

Host Data Bus

154

HDB5

I/O

1,Z,0

Host Data Bus

155

VSIO7

Digital Power Supply GND

156

HDB9

I/O

1,Z,0

Host Data Bus

157

HDB6

I/O

1,Z,0

Host Data Bus

158

HDB8

I/O

1,Z,0

Host Data Bus

159

HDB7

I/O

1,Z,0

Host Data Bus

160

VDC5

Digital Power Supply (2.5V)

161

XTL2

1, 0

Crystal Oscillating Circuit Output of the Clock for Decoder

162

XTL1

Crystal Oscillating Circuit Input of the Clock for Decoder

163

VSC5

Digital GND

164

MTST0

Test Pin. Normally “L”

165

AVS3

Analog GND

166

PWM2N

1, 0

PWM Output of Audio DAC. Default R Ch, Reverse Phase

167

PWM2P

1, 0

PWM Output of Audio DAC. Default R Ch, Forward Phase

168

AVD3

Analog Power Supply (2.5V)

169

AVD4

DSP, Power Supply for Audio DAC Clock (2.5V)

170

XTLO

1,0

DSP, Crystal Oscillating Circuit Output for the Audio DAC Clock

171

XTLI

DSP, Crystal Oscillating Circuit Input for the Audio DAC Clock

172

AVS4

DSP, GND for the Audio DAC Clock

173

AVS5

Analog GND

174

PWM1P

1, 0

PWM Output of Audio DAC. L Ch, Forward Phase

175

PWM1N

1, 0

PWM Output of Audio DAC. L Ch, Reverse Phase

176

AVD5

Analog Power Supply (2.5V)

Notes :

•

LRCK, BCK and PCMD are changed to 32-bit slot and 48-bit slot by command.

32-bit slot is output in 2's complements on an LSB-first basis and 48-bit slot is output in 2's complements on

an MSB-first basis.

•

*'s signal is able to convert to output by a command. (Refer to sub CPU Register 08h (W) of decoder part)

•

The GFS signal turns "H" upon coincidence between Frame Sync and the timing of interpolation protection.

•

XRAOF is a signal issued when a jitter margin of +28F is exceeded by the 32K RAM.

•

C2PO is a signal to indicate data error.

•

XUGF is a negative Frame Sync pulse obtained from the EFM signal before Frame Sync protection is

effected.

•

GTOP monitors the state of Frame Sync protection. ("H" : Sync protection window released)

•

XPLCK is an inversion of the EFM PLL clock. The PLL is designed so that the falling edge of XPLCK

coincides with a change point of the EFM signal.

•

RFCK is a signal generated at 136-µs periods using a crystal oscillator.

•

LOCK is sampling the GFS at 460Hz and outputs "H" when GFS is "H".

("L" outputs when "L" is output eight times in succession or inputs when LKIN is "H".)

Summary of Contents for GCR-8481B

Page 1: ...5ms Average Access Time Max 7 200KB sec Sustained Transfer rate GCR 8481B Max 7 800KB sec Sustained Transfer rate GCR 8521B Photo CD Multisession Disc Spec compliant Multimedia MPC 3 Spec compliant Power Tray Loading Ejection Mechanism 3 Way Eject support Software O C Button Emergency Eject Closed Enclosure Built in ATAPI Interface Controller Software Volume Control 8 Times Digital Filter for CD A...

Page 2: ... Ripple 5V Less than 100mVp p 12V Less than 100mVp p Current 5V 0 9A Maximum 12V 1 5A Maximum 5 AUDIO PERFORMANCE Frequency Response 20Hz 20KHz 3dB S N Ratio IHF A 20 KHz LPF 80 dB Typical at 1 KHz 0dB 75 dB Limit at 1 KHz 0dB T H D IHF A 20 KHz LPF 0 05 Typical at 1 KHz 0dB 0 15 Limit at 1 KHz 0dB Channel Separation IHF A 20 KHz LPF 80 dB Typical 70 dB Limit Output Level 1kHz 0dB 47KΩ Load 0 7Vrm...

Page 3: ...TOR SLED MOTOR LOADING MOTOR FOCUS COIL TRACKING COIL M63026FP MOTOR DRIVE Disc Motor unit Optical Pick up CXA2581N RF Amp CXD3045R DSP Decoder DRAM System controller 33 86MHz 40MHz I F Cable H O S T AUDIO Circuitry R ch L ch Line out A B C D 1 2 3 4 5 32 BLOCK DIAGRAM ...

Page 4: ... LED flickers but Speaker is silent 21 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 FOK H FEO TP15 signal generation Rotate disc Tracking Servo On TEO TP14 Signal generation Spindle Servo On SPO TP25 Signal generation Read TOC A...

Page 5: ...V and GND Does H output in IC501 pin Check and replace R705 R706 Q701 and LED701 Is the CLOCK Frequency of IC501 pin 33 86MHz Check the power input pattern Check IC501 Check and replace X501 33 86MHz X502 40MHz Is the CLOCK Frequency of IC501 pin 33 86MHz Check and replace IC501 YES OK NG YES YES NO NO NO 109 171 171 A 1 A 1 ...

Page 6: ...in Is the 1 35V at IC201 pin Check the pattern from IC501 pin to IC201 pin Check IC501 Check the R190 and then replace IC102 Check the PN301 and then replace the Sled Motor YES YES YES YES NO NO Replace IC201 NO NO 73 41 25 74 106 41 CH1 PIN74 DA0 CH2 PIN73 DA1 CH1 TP4 CH2 TP5 CH3 TP6 CH4 TP7 Fig B 1 DA0 and DA1 Signals Fig B 2 TP4 TP5 TP6 and TP7 Signals ...

Page 7: ...replace IC102 Check R118 and replace IC501 YES YES NO NO 1 4 12 Does the focus search signal appear at FAO TP9 Refer to Fig D 1 Is the 1 35V at IC201 pin Check the R190 and then replace IC102 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 ...

Page 8: ...ttern 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 FAO Signal Fig D 2 Focus Search Signal D 1 ...

Page 9: ...o 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 TP15 when the R504 opened Refer to Fig E 2 YES YES YES NO NO Replace IC501 Replace IC501 Replace Pick Up NO Do the signal appear at TP15 FEO and TP19 SENS Refer to Fig E 3 Does the signal appear at FOK TP18 during focus search Refer to Fig E 1 E Disc doesn t rotate ...

Page 10: ...27 Fig E 3 FEO Signal CH1 TP15 FEO Fig E 4 MDP Signal CH1 TP25 MDP Fig E 1 FOK F Signal CH1 TP10 F CH2 TP18 FOK Fig E 2 S Curve R505 Open CH1 TP15 S Curve ...

Page 11: ...area on the disc read Does LED flicker Does the other disc operate normally Normal Disc is defective YES YES NO 11 NO Does RFAC signal TP16 and RFDC signal TP17 appear Is Spindle Servo ON Does MDP signal TP25 appear YES YES NO NO NO Does A B C D signal appear at IC102 pin 6 7 8 9 Replace IC102 Replace IC102 Replace IC501 Replace Main Circuit Board or MD Ass y NO Refer to C The Laser of Pick Up doe...

Page 12: ... and 2 5V 9 NO Check the R602 8 Does H signal appear at IC501 pin YES NO 108 Check the IC501 pin and then replace IC501 108 Check C702 YES YES YES Are L ch R ch signals appear at JK701 and Audio Line out connector each NO Check JK701 and L701 L703 Does Audio signal appear at IC701 pin NO 1 7 Is the voltage of IC701 pin 2 5V 6 NO Replace IC701 G During Audio CD play LED flickers but Speaker is sile...

Page 13: ...ctor and Line or Jack normal NO Check the JK801 and Audio line pattern YES Check your sound card Audio Cable Speaker Volume and Headphone Jack Fig G 1 PWM Signal CH1 PIN6 of IC601 CH2 PIN10 of IC601 Fig G 2 Audio Signal CH2 PIN3 of IC601 CH2 PIN12 of IC601 G 1 ...

Page 14: ... shift to find the track on the Disc 3 RF Signal A B C D RF Signal is converted to Data Signal in One Chip IC IC501 Three signals Focus Error Signal Tracking Error Signal and RF Signal above are I V converted and amplified at the IC102 and then are transmitted to One Chip IC IC501 to generate the Servo Control Signal and Data Signal Red laser Pick Up module Tracking Focusing B C E F D A ...

Page 15: ...C SUM O RFAC RF SUM Output 19 TE_BAL I TE Control 5 GND I GND 20 CE O Center Error Signal Output 6 A I RF Input A Signal 21 CEI CE Amp Inverted 7 B I RF Input B Signal 22 Vcc I Vcc 8 C I RF Input C Signal 23 RFG I RFAC Low Frequency Gain Control 9 D I RF Input D Signal 24 BST I EQ Boost Volume Control 10 E I RF Input E Signal 25 VFC I EQ Cut OFF Frequency Control 11 F I RF Input F Signal 26 RFC I ...

Page 16: ... Slide current sense 2 5 SL2 Slide non inverted output 2 6 SL2 Slide inverted output 2 7 GND GND 8 RSL1 Slide current sense 1 9 SL1 Slide non inverted output 1 10 SL1 Slide inverted output 1 11 GND GND 12 W Motor drive output W 13 V Motor drive output V 14 U Motor drive output U 15 RSP Spindle current sensie 16 HW HW sensor amp input 17 HW HW sensor amp input 18 HV HV sensor amp input 19 HV HV sen...

Page 17: ...block Subcode P W Processor 32K RAM EFM Timing Generator Subcode Q Processor XRD XWR XCS XTL1 XINT XWAT XTL2 PWM2N PWM2P FOK PWM1N 175 167 166 161 162 PWM1P MIRR DFCT 174 OP Amp DAC SERVO DSP Auto Sequencer 8bit A D OP Amp Analog SW SAO TAO FAO BSSD DOUT DAC I F CD DSP I F CPU Interface FOK MIRR DFCT XTLO XTLI 170 171 Digital PLL ASY Sync protector PCO V DD Vss 52 FILI 51 FILO 50 CLTV 53 ASYI 57 A...

Page 18: ...lay RWM1 Signal Output 15 VSC0 Digital GND 16 DOUT O 1 0 Digital Out Output 17 VDIO0 Digital Power Supply 3 3V 18 SSTP I Disc Inner Track Detection Signal Input 19 MDP O 1 Z 0 Control Output of Spindle Motor 20 PWMI I External Terminal Input of Spindle Motor 21 DFCT I O 1 0 Defect Signal In Output 22 ATSK I Pin for Anti Shock It set to L When is not used 23 MNT0 O 1 0 MNT0 XRAOF Signal Output 24 M...

Page 19: ...put 54 AVS1 Analog GND 55 RFAC I EFM Signal Input 56 BIAS I Asymmetry Circuit Constant Current Input 57 ASYI I Asymmetry Comparator Voltage Input 58 ASYO O 1 0 EFM Full Swing Output L VSS H VDD 59 AVD1 Analog Power Supply 2 5V 60 VDC2 Digital Power Supply 2 5V 61 VDC3 Digital Power Supply 2 5V 62 VSC2 Digital GND 63 VSC3 Digital GND 64 FOK I O 1 0 Focus OK Signal IN OUT 65 MIRR I O 1 0 Mirror Sign...

Page 20: ...pt input port 87 PF1 EC2Z 16 bit capture timer counter external Event input port 88 PF0 89 PE7 CINT 16 bit capture timer counter capture Input port 90 PE6 91 PE5 92 PE4 INT4Z I O 1 0 External interrupt Input port 93 PE3 INT3Z 94 PE2 95 PE1 96 PE0 97 VSIO3 Digital Power Supply GND 98 PC7 99 PC6 100 PC5 101 PC4 I O 1 0 Port C 102 PC3 8 bit In Output port 103 PC2 104 PC1 105 PC0 106 PB7 107 PB6 108 P...

Page 21: ... Signal Positive Logic 129 XHAC I DMA Acknowledge Signal from Host Negative Logic 130 REDY O Z 0 Host I O Channel Ready Signal Open Drain Output Negative Logic 131 VDIO4 Digital Power Supply 3 3V 132 VDC4 Digital Power Supply 2 5V 133 VSC4 Digital GND 134 XHRD I Data Read Strobe Signal from Host 135 XHWR I Data Write Strobe Signal from Host 136 HDRQ O 1 Z 0 DMA Request Signal to Host Positive Logi...

Page 22: ... L Ch Forward Phase 175 PWM1N O 1 0 PWM Output of Audio DAC L Ch Reverse Phase 176 AVD5 Analog Power Supply 2 5V Notes LRCK BCK and PCMD are changed to 32 bit slot and 48 bit slot by command 32 bit slot is output in 2 s complements on an LSB first basis and 48 bit slot is output in 2 s complements on an MSB first basis s signal is able to convert to output by a command Refer to sub CPU Register 08...

Page 23: ... 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 A Separate the Pick Up Unit from the Mechanism Assy B Release 1 screws C and t...

Page 24: ...007 002 003 030 020 A02 A01 020 051 028 050 029 434 021 434 434 413 413 413 001 413 430 028 027 026 025 033 435 010 009 008 011 012 005 034 014 013 434 031 016 015 004 006 431 A B C D E F G H 1 2 3 4 5 EXPLODED VIEW 7 8 ...

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