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ORDER NO.

CRT3583

CD MECHANISM MODULE(S10.5COMP1)

CX-3164
This service manual describes the operation of the CD mechanism module incorporated in models listed in the table below. When performing repairs use this manual together with the specific manual for model under repair.
Model DEH-2800MP/XN/UC DEH-2850MP/XN/ES DEH-2800MP/XN/EW DEH-2800MPB/XN/EW DEH-2820MP/XN/EW DEH-281MP/XN/EW DEH-3850MP/XU/ES DEH-3850MPH/XU/GS DEH-3850MP/XU/CN DEH-P3800MP/XU/UC DEH-P4800MP/XU/EW DEH-P580MP/XN/UC DEH-P5800MP/XN/UC DEH-P6800MP/XN/EW DEH-P5850MP/XN/ES DEH-P5850MPH/XN/GS DEH-P480MP/XU/UC DEH-P4800MP/XU/UC DEH-P4850MP/XU/ES DEH-P4850MPH/XU/GS DEH-P4850MP/XU/CN DEH-P680MP/XN/UC DEH-P6800MP/XN/UC DEH-P6850MP/XN/ES CRT3569 CXK5752 CRT3567 CXK5750 CRT3566 CXK5750 CRT3564 CRT3565 CXK5752 CXK5752 CRT3557 CRT3558 CRT3563 CXK5750 CXK5750 CXK5752 CRT3556 CXK5750 CRT3555 CXK5752 Service Manual CRT3554 CD Mechanism Module CXK5752

PIONEER CORPORATION

4-1, Meguro 1-chome, Meguro-ku, Tokyo 153-8654, Japan PIONEER ELECTRONICS (USA) INC. P.O. Box 1760, Long Beach, CA 90801-1760, U.S.A. PIONEER EUROPE NV Haven 1087, Keetberglaan 1, 9120 Melsele, Belgium PIONEER ELECTRONICS ASIACENTRE PTE. LTD. 253 Alexandra Road, #04-01, Singapore 159936

PIONEER CORPORATION 2005
K-ZZA. OCT. 2005 Printed in Japan

1

2

3

4

CONTENTS
A

1. CIRCUIT DESCRIPTIONS ............................................................................................................................... 3 2. MECHANISM DESCRIPTIONS...................................................................................................................... 20 3. DISASSEMBLY ............................................................................................................................................... 22

B

C

D

E

F

2

CX-3164
1 2 3 4

5

6

7

8

1. CIRCUIT DESCRIPTIONS
UPD63763CGJ, multifunctional LSI used in this device, has built-in CD-ROM decoder and MP3/WMA decoder, as shown in Fig.1.0.1, as well as the conventional CD block, allowing to play CD-ROMs, in which MP3/WMA files are recorded, while the recent mainstay of the CD LSI is the LSI integrating the core DSP with DAC or RF amplifier, which are generally used as peripheral circuits.
A

A-F
SRAM(1Mbit)

CD-ROM
RF amplifier decoder

B

Buffer memory controller(BMC)
MP3/WMA
decoder

EFM

Signal processor

Digital servo

DAC
C

UPD63763CGJ

Audio output

Microcomputer

D

Fig.1.0.1 Block diagram of CD LSI UPD63763CGJ

E

F

CX-3164
5 6 7 8

3

1

2

3

4

1.1 PREAMPLIFIER BLOCK (UPD63763CGJ: IC201)
A

In the preamplifier block, the pickup output signals are processed to generate signals that are used in the subsequent blocks: servo, demodulator, and control blocks. Signals from the pickup are I/V converted in the pickup with the preamplifier with built-in photo detectors, and after added with the RF amplifier, they are used to produce such signals as RF, FE, TE, and TE zero-cross signals. The preamplifier block is built in CD LSI UPD63763CGJ (IC201), whose parts are described individually below. Incidentally, as this LSI employs a single power supply (+ 3.3 V) specification, the reference voltages of this LSI and the pickup are the REFO (1.65 V) for both. The REFO is an output obtained from REFOUT in the LSI via the buffer amplifier, and is output from the pin 133 of this LSI. All measurements will be performed with this REFO as the reference. Caution: Be careful not to short-circuit the REFO and GND when measuring.

B

1.1.1 APC (Automatic Power Control) circuit
Since laser diodes have extremely negative temperature characteristics in optical output when driven in constant current, it is necessary to control the current with the monitor diodes in order to keep the output constant. This is the feature of the APC circuit. The LD current is obtained by measuring the voltage between LD1 and V3R3D(+ 3.3 V), and divide the value by 7.5 (ohms), which becomes about 30 mA.

Pickup Unit

CD CORE UNIT

C
MD
5 5
143

PD
REG 1.25V

VR

7

7

+ 6.5k 1k V3R3D(+ 3.3 V) 2R4 × 2

+ -

LD-

15

15

6.5k 100/16

LD+

+

14

14

2R7 142

Vref

LD
1k

+ -

APN
100k

2SA1577

D

110k

100k

3p

LDS

UPD63763CGJ

E

Fig.1.1.1 APC

F

4

CX-3164
1 2 3 4

5

6

7

8

1.1.2 RF and RFAGC amplifiers
The output from the photo-detector (A + C) and (B + D) is provided from the RFO terminal as the RF signal (which can be used for eye-pattern check), after it is added, amplified, and equalized inside this LSI. The low frequency component of the voltage RFO is calculated as below. RFO = (A + B + C + D) x 2 The RFO is used for the FOK generation circuit and RF offset adjustment circuit. The RFO signal, output from the pin 119, is A/C-coupled externally, input to the pin 118, and amplified in the RFAGC amplifier to obtain the RFAGC signal. Also, this LSI is equipped with the RFAGC auto-adjustment function, explained below, which switches feedback gains of the RFAGC amplifier so that the RFO output will be 1.5 V. This RFO signal is also used for the EFM, DFCT, MIRR, and RFAGC auto-adjustment circuits.
A

B

119

118

CD CORE UNIT UPD63763CGJ

AGCI

RFO

RFRF2EQ2

123 122
1.2k 22p

4.7k

120
1.2k 56p 5.6k

4p

10k

10k

EQ1121
116

+
15.2k 15.2k

+ -

7.05k

+

35k 20k

AGCO

11.2k

To DEFECT/A3T detection RFOFF setup

Pickup Unit
VREF
P3 P7 P9 A+C 13 13 A C
124 10k 125 10k 8.8k 111k

For RFOK generation

C

+ -

R2 61.0k

+ + -

FEO

136

VREF

FE A/D

P2 P4 P8 B+C 6 6 D B
127 10k 126 10k

+ -

61.0k

FEFEOFF setup

135

8.8k

VREF

D

Fig.1.1.2 RF/AGC/FE

E

F

CX-3164
5 6 7 8

5

1

2

3

4

1.1.3 Focus error amplifier
A

The photo-detector outputs (A + C) and (B + D) are passed through the differential amplifier and the error amplifier, and (A + C - B - D) is provided from the pin 136 as the FE signal. The low frequency component of the voltage FE is calculated as below. FE = (A + C - B - D) x 8.8k / 10k x 111k / 61k x 160k / 72k = (A + C - B - D) x 3.5 For the FE outputs, an S-shaped curve of 1.5 Vp-p is obtained with the REFO as the reference. The cutoff frequency for the subsequent stage amplifiers is 14.6 kHz.

1.1.4 RFOK circuit
This circuit generates the RFOK signal, which indicates the timing to close the focus loop and focus-close status during the play mode, from the pin 55. As for the signal, "H" is output in closing the focus loop and during the play mode. Additionally, the RFOK becomes "H" even in a non-pit area, since the DC level of the RFO signal is peak-held in the subsequent digital block and compared at a certain threshold level to generate the RFOK signal. Therefore, the focus is closed even on a mirror-surface area of a disc. This signal is also supplied to the microcomputer via the low-pass filer as the FOK signal, which is used for protection and gain switching of the RF amplifier.

B

1.1.5 Tracking error amplifier
The photo-detector outputs E and F are passed through the differential amplifier and the error amplifier to obtain (E - F), and then provided from the pin 139 as the TE signal. The low frequency component of the voltage TE is calculated as below. TEO = (E - F) x 63k / 112k x 160k / 160k x 181k / 45.4k x 160k / 80k = (E - F) x 4.48 For the TE output, TE waveform of about 1.3 Vp-p with the REFO as the reference. The cutoff frequency in the subsequent is 21.1 kHz.

C

CD CORE UNIT
Pickup Unit

UPD63763CGJ
TE A/D
TEOFF setup
+ + + 139 47p 80k 160k 138 45.36k 161k

TEO

D
P5 P10 E
11

TE-

11

E

130 112k 63k

VREF

+ -

45.36k

+

+ -

TE2
140 10000p

P1 P6

-

160k

160k 20k 60k

F

9

9

F

129 112k 63k 141

TEC
-

VREF

+

Inside TEC

E

Fig.1.1.3 TE

F

6

CX-3164
1 2 3 4

5

6

7

8

1.1.6 Tracking zero-cross amplifier
The tracking zero-cross signal (hereinafter referred to as TEC signal) is obtained by amplifying the TE signal by fourfold, and used to detect the tracking-error zero-cross point. As the purpose of detecting the zero-cross point, the following two points can be named: 1. To use for track-counting in the carriage move and track jump modes 2. To use for detecting the direction in which the lens moves in tracking close. (Used in the tracking brake circuit to be explained later.) The frequency range of the TEC signal is from 300 Hz to 20 kHz, and TEC voltage = TE level x 4 The TEC level can be calculated at 4.62 V, which, at this level, exceeds the D range of the operational amplifier, and clips the signal, but, because the CD LSI only uses the signal at the zero-cross point, it poses no particular problem.
A

1.1.7 EFM circuit
The EFM circuit converts the RF signal into digital signals of 0 and 1. The AGCO signal output from the pin 116 is A/Ccoupled externally, input to the pin 114, and supplied to the EFM circuit. Missing RF signal due to scratches and stains on the disc, and asymmetry of the upper and lower parts of the RF, caused by variation in disc production, cannot be entirely eliminated in AC coupling process, the reference voltage ASY of the EFM comparator is controlled, using the probability that 0 and 1 occur at 50%. Thus, the comparator level will always stay around the center of the RFO signal. This reference voltage ASY is generated by passing the EFM comparator output through the low-pass filter. The EFM signal is output from the pin 111.

B

C

Vdd

UPD63763CGJ
112

ASY
EFM signal

RFI
114

+ Vdd
111 2k

EFM
D

+
40k

+ 1.5k 7.5k

40k

E

Fig.1.1.4 EFM

F

CX-3164
5 6 7 8

7

1

2

3

4

1.2 SERVO BLOCK (UPD63763CGJ: IC201)
A

The servo block performs servo control such as error signal equalizing, in-focus, track jump and carriage move. The DSP block is the signal-processing unit, where data decoding, error correction, and compensation are performed. The FE and TE signals, generated in the preamplifier stage, are A/D-converted, and output drive signals for the focus, tracking, and carriage systems via the servo block. Also, the EFM signal is decoded in the signal-processing unit, and ends up in outputting D/A-converted audio signals through the D/A converter. Furthermore, in this decoding process, the spindle servo error signal is generated, supplied to the spindle servo block, and used to output the spindle drive signal. Each drive signal for focus, tracking, carriage, and spindle servos (FD, TD, SD, and MD) are output as PWM3 data, and then converted to analog data through the LPF. These drive signals, after changed to analog form, can be monitored with the FIN, TIN, CIN, and SIN signals, respectively. Subsequently, the signals are amplified and supplied to the actuator and motor for each signal.

B

1.2.1 Focus servo system
The main equalizer of the focus servo consists of the digital equalizer block. The figure 1.2.1 shows the block diagram of the focus servo system. In the focus servo system, it is necessary to move the lens within the in-focus range in order to close the focus loop. For that purpose, the in-focus point is looked for by moving the lens up and down with the focus search voltage of triangular signal. During this time, the rotation of the spindle motor is retained at a certain set speed by kicking the spindle motor. The servo LSI monitors the FE and RFOK signals and automatically performs the focus-close operations at an appropriate timing. The focus-close operation is performed when the following three conditions are satisfied at the same time: 1) The lens moves toward the disc surface. 2) RFOK = "H" 3) The FE signal is zero-crossed. Consequently, the FE converges to "0" (= REFO). When the above-mentioned conditions are met and the focus loop is closed, the FSS bit is shifted from "H" to "L," and then, in 10 ms, the microcomputer starts monitoring the RFOK signal obtained through the low-pass filter. If the RFOK signal is determined to be "L," the microcomputer takes several actions including protection. Fig.1.2.2 shows a series of actions concerning the focus close operations. (It shows a case where the focus loop cannot be closed.) With the focus mode selector displaying 01 in the test mode, pressing the focus close button, allows to check the Sshaped curve, search voltage, and actual lens behavior.

C

D

IC201 UPD63763CGJ A+C B+D
E

IC301 BA5835FP

125 128

FE AMP

A/D

DIG. EQ CONTROL PWM FD
101 6 11 12

FOP LENS FOM

FOCUS SEARCH TRIANGULAR WAVE GENERATOR

Fig.1.2.1 Block diagram of the focus servo system
F

8

CX-3164
1 2 3 4

5

6

7

8

Search start
A

Output from FD terminal

A blind period

The broken line in the figure is assumed in the case without focus servo.

FE controlling signals

You can ignore this for blind periods.
B

FSS bit of SRVSTS1 resistor

RFOK signals The status of focus close is judged from the statuses of FSS and RFOK after about 10 mS.

Fig.1.2.2 Timing chart for focus close operations
C

1.2.2 Tracking servo system
The main equalizer of the tracking servo consists of the digital equalizer block. The figure 1.2.3 shows the block diagram of the tracking servo system.

IC201 UPD63763CGJ E F

IC301 BA5835FP
D

130 129

TE AMP

A/D

DIG. EQ CONTROL PWM TD
103 3 14 13

TOP TOM

LENS

JUMP PARAMETERS

E

Fig.1.2.3 Block diagram of the tracking servo system

F

CX-3164
5 6 7 8

9

1

2

3

4

(a) The track jump operation is automatically performed by the auto-sequence function inside the LSI with a command from the microcomputer. For the track jumps used in the search mode, a single track jump and four to 100 multi-track
A

jump are available in this system. In the test mode, out of these track jumps, 1, 32, and 32 * 3 track jumps, as well as carriage move can be performed and checked in mode selection. In a track jump, the microcomputer sets about half the number of the total tracks to jump (about five tracks for a 10-track jump), and the set number of tracks are counted using the TEC signal. By outputting the brake pulse for a certain period of time (set by the microcomputer) from the time the set number is counted, and stopping the lens, the tracking loop can be closed so that the normal play can be continued. Also, in order to facilitate closing of the tracking loop in a track jump, the brake circuit is kept ON for 50 msec, after the brake pulse is stopped, for increasing the tracking servo gain. The FF/REW action in the normal operation mode is realized by performing single jumps consecutively. The speed is approximately 10 times faster than in the normal mode. (b) Brake circuit

B

Since the servo loop is not closed very well in the setup mode and track jump mode, the brake circuit is used for stabilizing the servo-loop close operation. The brake circuit detects the direction in which the lens moves, and outputs only the drive signal for the direction opposite to the movement to slow down the lens, thereby stabilizing the tracking servo-loop close operation. Additionally, the off-track direction is determined from the TEC and MIRR signals, as well as their phase relation.

BRAKE

C

TD

t2 t1
KICK

TEC

ON T. BRAKE OFF GAIN UP

D

EQUALIZER

GAIN NORMAL NORMAL OPEN

T. SERVO CLOSED

Fig.1.2.4 Single-track jump

E

F

10

CX-3164
1 2 3 4

5

6

7

8

TD

t1 t2

A

TEC (10 TRACK) GAIN UP EQUALIZER

50 mS
NORMAL ON

T. BRAKE

OFF OPEN CLOSED

B

SERVO

SD

t
2.9mS (4.10 TRACK JUMP) 5.8mS (32 TRACK JUMP)

Fig.1.2.5 Multi-track jump
C

LENS MOVING FORWARDS (INNER TRACK TO OUTER)

LENS MOVING BACKWARDS

TEC

TZC (TEC "SQUARED UP" ) (INTERNAL SIGNAL )

D

MIRR

MIRR LATCHED AT TZC EDGES SWITCHING PULSE = EQUALIZER OUTPUT (SWITCHED)

E

DRIVE DIRECTION

REVERSE

FORWARD

Time

Note : Equalizer output assumed to hava same phase as TEC.

Fig.1.2.6 Track brake

F

CX-3164
5 6 7 8

11

1

2

3

4

1.2.3 Carriage servo system
A

The carriage servo system inputs the output of the low frequency component from the tracking equalizer (information on the lens position) to the carriage equalizer, and, after the gain is increased to a certain level, outputs the drive signal from the LSI. This signal is applied to the carriage motor via the driver IC. Specifically, since it is necessary to move the whole pickup to the FORWARD direction when the lens offset reaches a certain level during the play mode, the equalizer gain is set to output higher voltage than the carriage motor starting voltage at this time. In actual operations, a certain threshold level is preset in the servo LSI for the equalizer output, and only when it exceeds the threshold level, the drive voltage will be output. This can reduce the power consumption. Also, before the whole pickup starts moving, the equalizer output voltage may exceed the threshold level a few times, due to such causes as eccentricity of discs. In this case, the output waveform of the drive voltage from the LSI assumes a pulselike form.

B

IC201 UPD63763CGJ

IC301 BA5835FP

From TRACK EQ.

DIG. EQ CONTROL PWM SD
105 24 17 18

LCOP LCOM M CARRIAGE MOTOR

KICK, BRAKE REGISTERS
C

Fig.1.2.7 Block diagram for the carriage servo block

TRACKING DRIVE (LOW FREQUENCY)

D
LENS POSITION

DRIVE ON/OFF THRESHOLD CRG DRIVE (INSIDE UPD63763CGJ)

E

CRG MOTOR VOLTAGE CARRIAGE MOVED AT THESE POINTS

Fig.1.2.8 Waveforms of the carriage signal

F

12

CX-3164
1 2 3 4

5

6

7

8

1.2.4 Spindle servo system
In the spindle servo system, the following modes are available: 1) Kick Used to accelerate the disc rotation in the setup mode. 2) Offset a. Used in the setup mode after the kick mode, until the TBAL adjustment is completed. b. Used during the play mode when the focus loop is unlocked, until it is locked again. In both cases, the mode is used to keep the disc rotation approximately normal. 3) Applicable servo CLV servo mode, used in the normal operation. In the EFM demodulation block, by WFCK/16 sampling whether the frame sync signal and the internal frame counter output are synchronized, a signal is created to show if they are "in-sync" or "non-sync." The status is not recognized as asynchronous until the signal is "non-sync" for eight consecutive times; otherwise it is recognized as synchronous. In the applicable servo mode, the leading-in servo mode is automatically selected in the asynchronous status, and the normal servo mode in the synchronous status. 4) Brake Used to stop the spindle motor. In accordance with the microcomputer's command, the brake voltage is sent out from the servo LSI. At this time, the EFM waveform is monitored in the LSI, and when the longest EFM pattern exceeds a certain interval (or the rotation slows down enough), a flag is set inside the LSI, and the microcomputer switches off the brake voltage. If a flag is not set within a certain period, the microcomputer shifts the mode from the brake mode to the stop mode, and retains the mode for a certain period of time. If the mode switches to this stop mode in the eject operation, the disc will be ejected after the period of time mentioned above elapses. 5) Stop Used when the power is turned on and during the eject operation. In the stop mode, the voltage in both ends of the spindle motor is 0 V. 6) Rough servo Used in carriage feed (carriage move mode such as long search). By obtaining the linear velocity from the EFM waveform, the "H" or "L" level is input to the spindle equalizer. In the test mode, this mode is also used for grating confirmation.
A

B

C

D

IC201 UPD63763CGJ SPEED ERROR SIGNAL DSP BLOCK DIG. EQ PWM MD
107

IC301 BA5835FP

16 26 15

SOP SOM M SPINDLE MOTOR

EFM SIGNAL

PHASE ERROR SIGNAL

E

Fig.1.2.9 Block diagram of the spindle servo system

F

CX-3164
5 6 7 8

13

1

2

3

4

1.3 AUTOMATIC ADJUSTMENT FUNCTION
A

In this system, all the circuit adjustments are automated inside the CD LSI. All adjustments are performed whenever a disc is inserted or the CD mode is selected by pressing the source key. Details of each adjustment will be explained below.

1.3.1 TE, FE, and RF offset auto-adjustment
In this adjustment the TE, FE, and RF amplifier offsets of the preamplifier block in POWER ON are adjusted to the respective target values with the REFO as reference. (The target values for TE, FE, and RF offsets are 0 V, 0 V, and - 0.8 V, respectively.) Adjusting procedure 1) The microcomputer reads respective offsets through the servo LSI, when they are in LDOFF status. 2) The microcomputer calculates the voltages for correction from the values read in 1), and substitutes the corrected values to prescribed places to adjust.

B

1.3.2 Tracking balance (T.BAL) auto-adjustment
This adjustment equalizes the output difference of the E-ch and F-ch from the pickup by changing the amplifier gain inside the LSI. In actual operation, adjustment is performed so that the TE waveform becomes symmetrical on each side of the REFO. Adjusting procedure 1) After closing the focus loop, 2) Kick the lens in the radial direction to ensure the generation of the TE waveform. 3) The microcomputer reads the offset amount of the TE signal calculated in the LSI at the time through the servo LSI. 4) The microcomputer determines the offset amount is 0, positive, or negative. - When the offset amount is 0, the adjustment is completed. - When the offset amount is positive or negative, the amp gains for E-ch and F-ch should be changed, following a certain rule. Then, steps 2) to 4) are repeated until the offset amount becomes 0 or the repetition reaches the limit number of times.

C

1.3.3 FE bias auto-adjustment
D

E

This adjustment is to maximizes the RFO level by optimizing the focus point during the play mode, utilizing the phase difference between the 3T level waveform of the RF waveform and that of when focus error disturbance is input. This adjustment is performed at the same timing as the auto-gain control, which will be described later, since disturbance is input to the focus loop. Adjusting procedure 1) The microcomputer issues the command to introduce disturbance to the focus loop (inside the servo LSI). 2) The waver of the 3T component of the RF signal is detected in the LSI. 3) The relation between the 3T component above and the disturbance is processed inside the LSI to detect the volume and direction of the focus offset. 4) The microcomputer issues a command and reads out the detected results from the servo LSI. 5) The microcomputer calculates the necessary correction and substitutes the result to the bias adjustment term inside the servo LSI. Additionally, in this adjusting, a series of steps are repeated for better adjustment accuracy, the same as in the auto-gain control.

F

14

CX-3164
1 2 3 4

5

6

7

8

1.3.4 Focus and tracking AGC
This adjustment is to automatically adjust the focus and tracking servo loop gains. Adjusting procedure 1) Introduce disturbance to the servo loop. 2) The error signals (FE and TE) when disturbance is introduced are extracted through the band pass filter, to obtain the G1 and G2 signals. 3) The microcomputer reads the G1 and G2 signals through the servo LSI. 4) The microcomputer calculates the necessary correction and performs the loop gain adjustment inside the servo LSI. For increased adjustment accuracy, the same adjustment process is repeated a few times.
A

1.3.5 RF level auto-adjustment (RFAGC)
This adjustment is to adjust the dispersion of the RF level (RFO), which may be caused by mechanism or disc-related factors, to a steady value for reliable signal transmission. The adjustment is performed by changing the amp gain between RFO and RFAGC. Adjusting procedure 1) The microcomputer issues a command and reads out the output from the RF level detection circuit inside the servo LSI. 2) From the read values, the microcomputer calculates the amp gain to change the RFAGC level to the target. 3) The microcomputer sends a command to the servo LSI to adjust the amp gain to the level calculated in 2). This adjustment is performed 1) when only the focus close operation is completed during the setup mode, and 2) immediately before the setup is completed (or when the play mode is about to start).
B

C

1.3.6 Adjustment of gains in preamplifier stage
In this adjustment, when reflected beams from the disc surface are extremely weak, such as when the lens is dirty, or a CD-RW is played, gains in the whole RFAMP block (FE, TE, and RF amplifiers) are increased by + 6 dB or + 12 dB, depending on the situation. Adjusting procedure When the system determines that the reflected beams from the disc surface are extremely weak during the setup mode, the whole RFAMP gains will be increased by + 6 dB or + 12 dB.

1.3.7 Initial values in adjustment
All automatic adjustments immediately after inserting a disc are performed based on the initial values. Automatic adjustments by source change or ACC ON are basically performed using the previous adjustment values as the initial values.

D

E

F

CX-3164
5 6 7 8

15

1

2

3

4

1.3.8 Coefficient display of adjustment results
A

B

C

For some of the adjustments (FE and RF offset, FZD cancel, F and T gains, and RFAGC), the adjustment results can be displayed and confirmed in the test mode. The coefficient display in each auto adjustment is as follows: 1) FE and RF offset Reference value = 32 (coefficient of 32 indicates that no adjustment is required) The value is displayed in the unit of approximately 32mV. Ex. When the FE offset coefficient is 35, 35 - 32 = 3 x 32 mV = 96 mV The correction is about +96 mV, which means the FE offset before adjustment is - 96 mV. 2) F and T gain adjustment Reference value for focus and tracking = 20 The displayed coefficient / the reference value indicates the adjusted gain. Ex. When the AGC coefficient is 40, adjustment of 40 / 20 = 2 times (+ 6 dB) has been performed. (It means that the original loop gain was half the target, and the whole gain was doubled to obtain the target value.) 3) RF level adjustment (RFAGC) Reference value = 8 The coefficient of 9 to 15 indicates to increase the RF level (for more gains). The coefficient of 7 to 10 indicates to decrease the RF level (for less gains). When the coefficient changes by 1, the gain changes by 0.7 to 1 dB. When the coefficient is 15, the gain is the maximum at TYP + 7.9 dB. When the coefficient is 0, the gain is the minimum at TYP - 4.6 dB.

D

E

F

16

CX-3164
1 2 3 4

5

6

7

8

1.4 POWER SUPPLY AND LOADING BLOCK
For the power supply for this system, the VD (7.5 ± 0.5 V) and the VDD (5.0 ± 0.25 V), which are supplied from the motherboard, are used. The three power supplies, the VD mentioned above (for the drive system), the V3R3D obtained from the VD via the 3.3 V regulator (for the control system: 3.3 V) and the VDD (for the microcomputer: 5 V), are used in this system. The microcomputer controls ON/OFF with "CONT", except for Load/Eject of the CD driver, and ON/OFF of 3.3 V with "CD3VON". For ON/OFF of the Loading drive, no particular control terminals are available, but the input signal "LOEJ" assumes an equivalent role. Also, the LCO output switches LOADING MODE and CARRIAGE MODE with "CLCONT".
A

CN901
B

19 20 PGND

18 LCOP 20 IC301 LOADING M MOTOR BA5835FP LCOM 17 10 19 9 22 CONT LOEJ 21 CLCONT 41 40 47

1 2

VD

28

C

VD 2 V3R3D

2

IC701 PE5505A

IC203
3

4

NJM2886DL3-33 12 18 GND 49 9 11 VDCONT VDD 5VDD

D

4

30 DSCSNS

31 8EJ

32 12EJ

S903 S905 S904
Fig.1.4.1 Power supply/loading system circuit block

E

CLCONT

Loading Mode

Carriage Mode

Loading Mode

F

Fig.1.4.2 Loading/carriage mode shift CX-3164
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1

2

3

4

A

The load/eject operation is controlled with the status changes of the HOME switch (also used for clamp detection) on the mechanism unit and the three switches on the control unit. The ON/OFF statuses of these switches are respectively detected at the input port of the microcomputer. Using the detection results in the microcomputer, each status (A to E) is determined. The disc size detection (8 or 12 cm) is also performed through this status change. Each status is shown in Fig.1.4.3 and the status change in Fig.1.4.4.

DSCSNS 8SW 12SW HOME

Status SW1(S903) SW2(S905) SW3(S904) SW4(S901) Mechanism state

A OFF ON ON OFF With no disc

B ON ON ON OFF

C ON OFF ON OFF

D ON OFF OFF OFF

E ON ON ON ON Clamp state

B

Fig.1.4.3 DSCSNS status

LOADING 12cm
SW_ON

12EJ
C
SW CHANGES

SW_OFF

8EJ DSCSNS HOME CLCONT

CONTROL

LOEJ MOTOR STOP LOAD STOP It changes Load/Carriage

D

8cm 12EJ
SW CHANGES

8EJ DSCSNS HOME CLCONT

E
CONTROL

LOEJ MOTOR STOP LOAD Dead zone STOP

F

18

CX-3164
1 2 3 4

5

6

7

8

EJECT 12cm 12EJ 8EJ DSCSNS HOME

A

SW CHANGES CONTROL

CLCONT LOEJ MOTOR STOP EJECT STOP

B

8cm 12EJ

SW CHANGES

8EJ
C

DSCSNS HOME

CONTROL

CLCONT LOEJ MOTOR STOP EJECT Dead zone STOP
D

Fig.1.4.4 Status change in LOAD and EJECT modes

E

F

CX-3164
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19

1

2

3

4

2. MECHANISM DESCRIPTIONS
- Loading actions
A

1. When a disc is inserted, SW Arm L and R rotate and SW1 is switched from ON to OFF. When SW1 is switched from ON to OFF, the Load Carriage Motor is started and the rubber roller rotates. 2. If the disc is a 12cm-disc, SW3 is turned ON with SW Arm, and the microcomputer determines that the disc is a 12cmdisc. 3. In case of an 8cm-disc, SW3 is not turned ON, a clamp action is triggered, and the microcomputer determines that the disc is an 8cm-disc. (The left and right of SW Arm are coupled, and when only one side is pushed, the coupled joint will lock, and the arms will not open more than a certain width (SW3 will not be turned ON).) Pickup Unit

B

Load Carriage Motor

SW3
C

SW2

Rubber Roller

SW1
DISC

SW Arm L
D

SW Arm R

- Disc centering mechanism
1. 8cm-disc is centered by the Guide Pins and the Centering Pins. 2. 12cm-disc passes under the Guide Pins and the Centering Pins, and centered in the back position of the mechanism.
Centering Pin Centering Pin 8cm-Disc

E

Guide Pin

Guide Pin

Guide Pin 12cm-Disc

Centering Pin

F

20

CX-3164
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8

- Clamp actions mechanism
1. With an 8 or 12cm-disc centered on the spindle, the Detection Arm is moved. 2. The movement of the Detection Arm engages the Loading Rack with the 2-Stage Gear. 3. The Clamp Lever slides and lowers the Clamp Arm (the disc is clamped). At the same time, the Roller Up Arm is rotated, and the Rubber Roller is separated from the disc. Also the arm slides the Mechanical Lock Lever, turns the Mechanical Lock Arm, and releases the mechanical lock, completing the clamp operation. 4. When the clamp action is completed, the Clamp Lever rotates the Gear Lock Arm. When the arm is rotated, the Planet Gear is separated from the 2-Stage Gear and engaged with the gear of the pickup feed screw, and the carriage operation will start
Detection Arm
1 1

A

Clamp Arm

Feed Screw's Gear

Clamp Lever 3

Loading Rack
B

2

2-Stage Gear

8 7

Gear Lock Arm

4 5

Planet Gear Roller Up Arm
C

Rubber Roller
Mech Lock Arm

6

Mech Lock Lever

- Eject actions
1. When the Load Carriage Motor is rotated backward, and the pickup is fed to the inner periphery passing the home SW ON point, the eject action will start in the reverse order of the procedure mentioned earlier. 2. For a 12cm-disc, Eject is completed when SW3 is switched OFF, ON, and OFF again. 3. For an 8cm-disc, Eject is completed when SW2 is switched OFF, ON, and OFF again.

D

E

F

CX-3164
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21

1

2

3

4

3. DISASSEMBLY
A

- How to hold the Mechanism Unit
1. Hold the Upper and Lower Frames. 2. Do not hold the front portion of the Upper Frame, because it is not very solid.

B

Do not squeeze this area.

- Removing the Upper and Lower Frames
C

1. With a disc inserted and clamped in the mechanism, remove the two Springs (A), the six Springs (B), and the four Screws. 2. Turn the Upper Frame using the part "a" as a pivot, and remove the Upper Frame. 3. While lifting the Carriage Mechanism, remove it from the three Dampers. Caution: When assembling, be sure to apply some alcohol to the Dampers and assemble the mechanism in a clamped state.

B B

a Upper Frame

B B

B B
D

A Damper Damper A Carriage Mechanism Lower Frame

E

F

22

CX-3164
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7

8

- Removing the Guide Arm Assy
1. Remove the Upper and Lower Frames and set the mechanism to the eject mode. 2. Remove the two Screws and Bevel Gear Bracket. (Note that the gears will come off.) 3. Remove the two Springs from the left and right sides. 4. Slide the Guide Arm Assy to the left, and turn it upward. 5. When it is turned about 45 degrees, slide it to the right and remove. Caution: When assembling, assemble with the Bevel Gear Bracket moved to the direction of the arrow (1).
Bevel Gear Bracket 1
A

B

C

Spring 3

2

1

Guide Arm Assy Spring
D

E

F

CX-3164
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23

1

2

3

4

- How to remove the CD Core Unit
1. Apply Shorting Solder to the flexible cable of the Pickup, and disconnect it from the connector. 2. Unsolder the four leads, and loosen the Screw. 3. Remove the CD Core Unit. Caution: When assembling the CD Core Unit, assemble it with the SW in a clamped state so as not to damage it.
Shorting Solder

A

Screw

B

CD Core Unit Solder

- How to remove the Roller Arm Assy
1. Remove the Guide Arm Assy. 2. Remove the CD Core Unit. (If the Spring can be removed, the unit need not be removed, depending on the type of CD Core Unit.) 3. Remove the Spring. 4. Slide the Roller Arm Assy to the left.

C

Spring
D

Spring

Roller Arm Assy

E

F

24

CX-3164
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5

6

7

8

- How to remove the Pickup Unit
1. Make the system in the carriage mechanism mode, and have it clamped. 2. Remove the CD Core Unit and remove the leads from the Inner Holder. 3. Remove the Poly Washer, Change Arm, and Pickup Lock Arm. 4. While releasing from the hook of the Inner Holder, lift the end of the Feed Screw. Caution: When assembling, move the Planet Gear to the load/eject position before setting the Feed Screw in the Inner Holder. Assemble the sub unit side of the Pickup, taking the plate (Chassis) in-between. When treating the leads of the Load Carriage Motor Assy, do not make them loose over the Feed Screw.
Poly Washer Pickup Lock Arm Inner Holder Feed Screw
B

A

Change Arm

Planet Gear Pickup Rack

Chassis
C

Pickup

D

E

F

CX-3164
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25

1

2

3

4

- How to remove the Load Carriage Motor Assy
1. Make the system in the carriage mechanism mode, and have it clamped. 2. Release the leads (orange and purple) of Load Carriage Motor Assy from the CD Core Unit and remove the holder. 3. Remove the Poly Washer, Change Arm, and Pickup Lock Arm. 4. Remove the two Screws (A) and the Bevel Gear Bracket (Note that the gears will come off). 5. Remove the two Screws (B) and the Gear Bracket (remove the CD Core Unit, if necessary), and remove all the gears. 6. Remove the two Screws (C) and the Load Carriage Motor Assy. Caution: When assembling the Load Carriage Motor Assy, move it to the direction shown in the illustration (1). When treating the leads of the Load Carriage Motor Assy, do not make them loose over the Feed Screw.

Gear Bracket Screw B Screw A Bevel Gear Bracket

A

Poly Washer Change Arm Pickup Lock Arm

B

Load Carriage Motor Assy

Screw C

C

1

D

E

F

26

CX-3164
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5

6

7

8

- How to remove the Clamp Arm Assy
1. Make the system in the carriage mechanism mode, and set the mechanism to the eject mode. 2. Remove the three Springs. 3. While pressing the position A, turn the Clamp Arm Assy upward, slide it to the left, and remove. Caution: When assembling, place the boss of the Detection Pin in the cam unit of the Loading Rack.

A

Spring

B

Clamp Arm Assy Spring Detection Pin A Spring

place the boss in the cam
Detection Pin

C

- How to remove the Spindle Motor Assy
1. Make the system in the carriage mechanism mode, and have it clamped. 2. Remove the CD Core Unit and remove the leads from the Inner Holder. 3. Set the mechanism to the eject mode and remove the Clamp Arm Assy. 4. Set the mechanism to the clamped and move the Pickup to circumference. 5. Remove the two Screws, and remove the Spindle Motor Assy.

Screw
D

Spindle Motor Assy

E

F

CX-3164
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27