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Service Manual
CD MECHANISM MODULE
ORDER NO.
CRT2944
CX-3026
- 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-P250/XM/UC DEH-P250/XN/UC DEH-P2500/XM/UC DEH-P2500/XN/UC DEH-P25/XM/UC DEH-P25/XN/UC DEH-P2530R/XM/EW DEH-P2530R/XN/EW DEH-P2500R/XM/EW DEH-P2500R/XN/EW DEH-P2500RB/XM/EW DEH-P2500RB/XN/EW DEH-P2550/XM/ES DEH-P2550/XN/ES DEH-P350/XM/UC DEH-P350/XN/UC DEH-P3500/XM/UC DEH-P3500/XN/UC DEH-P4550/XM/ES DEH-P4550/XN/ES DEH-P4500R/XM/EW DEH-P4500R/XN/EW Service Manual CRT2981 CD Mechanism Module CXK5600 CRT2982
CRT2983 CRT2984
CRT2985
CONTENTS
1. CIRCUIT DESCRIPTIONS ...........................................2 2. MECHANISM DESCRIPTIONS.................................20 3. DISASSEMBLY .........................................................22
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 C PIONEER CORPORATION 2002
K-ZZA. NOV. 2002 Printed in Japan
1
2
3
4
A
1. CIRCUIT DESCRIPTIONS
Recently, Many CD LSIs have been one-chip LSIs where RF amplifier, DSP, audio DAC, post filter, and other circuits are integrated. This product uses this type CD LSI, UPD63712GC, which includes all functions necessary for CD player control. Basically, this system outputs the analog signal, and the digital output can be supported.
A-F
B
UPD63712GC Digital signal processing
EFM RF amplifier A/D converter
1 bit, Audio DAC
Drive output
C
Servo PWM output
Digital servo
CD-TEXT Post filter (SCF)
MPU interface
Microcomputer for system control
D
Analog output
Fig.1.0.1 Block diagram of CD LSI UPD63712GC
E
F
2 1 2
CX-3026/E
3
4
5
6
7
8
1.1 PREAMPLIFIER BLOCK (UPD63712GC: IC201)
In the preamplifier block, the pickup output signals are processed to generate signals that are used for the next-stage blocks: the servo block, demodulator, and control. After I/V-converted by the preamplifier with built-in photo detectors (inside the pickup), the signals are applied to the preamplifier block in the CD LSI UPD63712GC (IC201). After added by the RF amplifier in this block, these signals are used to produce necessary signals such as RF, FE, TE, and TE zero-cross signals. The CD LSI employs a single power supply system of + 3.3V. Therefore, the REFO (1.65V) is used as the reference voltage both for this CD LSI and the pickup. The LSI produces the REFO signal by using the REFOUT via the buffer amplifier and outputs from the pin 90. All the measurements should be made based on this REFO. Caution: Be careful not to short the REFO and GRD when measuring.
A
B
1.1.1 APC (Automatic Power Control)
A laser diode has extremely negative temperature characteristics in optical output at constant-current drive. To keep the output constant, the LD current is controlled by monitor diodes. This is called the APC circuit. The LD current is calculated at about 30mA, which is the voltage between LD1 and V+3A divided by 7.5 (ohms).
Pickup Unit(P10)
CD CORE UNIT(S10)
MD
5
5
2
PD
C
REG 1.25V + + 1k 150 k APC REG 1.25V
100 p
VR
7
7
6.5 k
LD-
15
15 100/16
1R5 x 5
R1
LD+
+
3p Vref APN 1 LD 1k + 100 k
14
14
2SB1132
D
110 k 100 k
R1 1SS355 3 PN LDS UPD63712GC 3p
E
Fig. 1.1.1 APC
F
CX-3026/E
3 7 8
5
6
1
2
3
4
A
1.1.2 RF and RFAGC amplifiers
The photo-detector outputs (A + C) and (B + D) are added, amplified, and equalized inside this LSI, and then provided as the RF signal from the RFI terminal. The RF signal can be used for eye-pattern check. The low frequency component of the RFI voltage is: RFO = (A + B + C + D) x 2 The RFO is used for the FOK generation circuit and RF offset adjustment circuit. The RFI output from the pin 71 is A/C-coupled outside this LSI, and returned to the pin 76 of this LSI. The signal is amplified in the RFAGC amplifier to obtain the RFAGC signal. This LSI is equipped with the RFAGC auto-adjustment function as explained below. This function automatically controls the RFO level to keep at 1.5V by switching the feedback gain for the RFAGC amplifier. The RFO signal is also used for the EFM, DFCT, MIRR, and RFAGC auto-adjustment circuits.
B
78
77
CD CORE UNIT(S10) UPD63712GC
R1
AGCI
RFO
RFRF2EQ2
2p 74 3p 75 20 p 72 47 p 1.2 k
5k + 15.2 k + 3.55 k +
5k
73 EQ1
1.2 k
76 AGCO
C
Pickup Unit(P10)
15.2 k
44 k
20 k
11.75 k To DEFECT/A3T detection
RFOFF setup For RFOK generation
VREF P2 P4 P8 VREF A+C A C + 13 13 82 10 k 83 10 k P3 P7 P9 B+C D B + 6 6 85 10 k 84 10 k 8.8 k 8.8 k
R2 61 k + 140 k 61 k FEOFF setup + FEO FE A/D FE92
93
VREF
D
E
Fig. 1.1.2 RF/AGC/FE
F
4 1 2
CX-3026/E
3
4
5
6
7
8
1.1.3 Focus error amplifier
The photo-detector outputs (A + C) and (B + D) are applied to the differential amplifier and the error amplifier to obtain the (A + C - B - D) signal, which is then provided from the pin 93 as the FE signal. The low frequency component of the FE voltage is: FE = (A + C - B - D) x 8.8k/10k x 111k/61k x 160k/72k = (A + C - B - D) x 3.55 The FE output shows 1.5Vp-p S-shaped curve based on the REFO. For the next-stage amplifiers, the cutoff frequency is 14.6kHz.
A
1.1.4 RFOK
The RFOK circuit generates the RFOK signal, which indicates focus-close timing and focus-close status during the play mode, and outputs from the pin 6. This signal is shifted to "H" when the focus is closed and during the play mode. The DC level of the RFI signal is peak-held in the digital block and compared with a certain threshold level to generate the RFOK signal. Therefore, even on a non-pit area or a mirror-surface area of a disc, the RFOK becomes "H" and the focus is closed. This RFOK signal is also applied to the microcomputer via the low-pass filer as the FOK signal, which is used for protection and RF amplifier gain switching.
B
1.1.5 Tracking error amplifier
The photo-detector outputs E and F are applied to the differential amplifier and the error amplifier to obtain the (E - F) signal, and then provided from the pin 96 as the TE signal. The low frequency component of the TE voltage is: TEO = (E - F) x 63k/112k x 160k/160k x 181k/45.4k x 160k/80k = (E - F) x 4.48 The TE output provides the TE waveform of about 1.16Vp-p based on the REFO. For the next-stage amplifiers, the cutoff frequency is 21.1kHz.
C
UPD63712GC CD CORE UNIT(S10) TE A/D TEOFF setup Pickup Unit(P10) + + P5 P10 VREF + P1 P6 F 9 9 F 86 112 k 63 k 98 + TEC E 11 11 E 87 112 k 63 k + 45.4 k 160 k 20 k 60 k + 97 TE2 33 p 80 k 160 k 95 45.4 k 161 k TE+ 96 TEO
D
160 k
R1
Inside TEC
VREF
E
Fig. 1.1.3 TE
F
CX-3026/E
5 7 8
5
6
1
2
3
4
A
1.1.6 Tracking zero-cross amplifier
The tracking zero-cross signal (hereinafter TEC signal) is obtained by amplifying the TE signal 4 times, and used to detect the tracking-error zero-cross point. By using the information on this point, the following two operations can be performed: 1. Track counting in the carriage move and track jump modes 2. Sensing the lens-moving direction at the moment of the tracking close (The sensing result is used for the tracking brake circuit as explained below.) The frequency range of the TEC signal is between 300Hz and 20kHz. TEC voltage = TE level x 4 The TEC level can be calculated at 4.64V. This level exceeds the D range of the operation amplifier, and the signal gets clipped. However, it can be ignored because the CD LSI only uses the signal at the zero-cross point.
B
1.1.7 EFM
The EFM circuit converts the RF signal into a digital signal expressed in binary digits 0 and 1. The AGCO output from the pin 76 is A/C-coupled in the peripheral circuit, fed back to the LSI from the pin 71, and sent to the EFM circuit inside the LSI. On scratched or dirty discs, part of the RF signal recorded may be missing. On other discs, part of the RF signal recorded may be asymmetric, which was caused by dispersion in production quality. Such lack of information cannot be completely eliminated by this AC coupling process. Therefore, by utilizing the fifty-fifty occurrence ratio of binary digits (0 and 1) in the EFM signal, the EFM comparator reference voltage ASY is controlled, so that the comparator level always stays around the center of the RFO signal. The reference voltage ASY is made from the EFM comparator output via the low-pass filter. The EFM signal is put out from the pin 68.
C
UPD63712GC Vdd
40 k
69 EFM signal
ASY
D
RFI 71 + Vdd 40 k
68 EFM 2k
40 k + 40 k
+ -
1.5 k
7.5 k
E
Fig. 1.1.4 EFM
F
6 1 2
CX-3026/E
3
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5
6
7
8
1.2 SERVO BLOCK (UPD63712GC: IC201)
The servo block controls the servo systems for error signal equalizing, in-focus, track jump and carriage move and so on. The DSP block is a signal-processing block, where data decoding, error correction, and compensation are performed. After A/D-converted, the FE and TE signals (generated in the preamplifier block) are applied to the servo block and used to generate the drive signals for the focus, tracking, and carriage servos. The EFM signal is decoded in the DSP block, and finally sent out as the audio signal after D/A-converted. In this decoding process, the spindle servo error signal is generated, supplied to the spindle servo block, and used to generate the spindle drive signal. The drive signals for focus, tracking, carriage, and spindle servos (FD, TD, SD, and MD) are provided as PWM3 data, and then converted to the analog data by the low-pass filter in the driver IC BA5996FP (IC301). These analog drive signals can be monitored by the FIN, TIN, CIN, and SIN signals respectively. Afterwards, the signals are amplified and applied to each servo's actuator and motor.
A
B
1.2.1 Focus servo system
In the focus servo system, the digital equalizer block works as its main equalizer. The figure 1.2.1 shows the block diagram of the focus servo system. To close the focus loop circuit, the lens should be moved to within the in-focus range. While moving the lens up and down by using the focus search triangular signal, the system tries to find the in-focus point. In the meantime, the spindle motor rotation is kept at the prescribed one by using the kick mode. The servo LSI monitors the FE and RFOK signals and automatically performs the focus close operations at an appropriate timing. The focus loop will close when the following three conditions are satisfied at the same time: 1) The lens moves toward the disc surface. 2) The RFOK signal is shifted to "H". 3) The FE signal is zero-crossed. At last, the FE signal comes to the zero level (or REFO). When the focus loop is closed, the FSS bit is shifted from "H" to "L". The microcomputer starts monitoring the RFOK signal obtained through the low-pass filter 10msec after that. If the RFOK signal is detected as "L", the microcomputer will take several actions including protection. The timing chart for focus close operations is shown in fig. 1.2.2. (This shows the case where the system fails focus close.) In the test mode, the S-shaped curve, search voltage, and actual lens movement can be confirmed by pressing the focus close button when the focus mode selector displays 01.
C
D
UPD63712GC A+C B+D
BA5996FP
82 85
FE AMP
A/D
DIG. EQ CONTROL FD PWM 52 6 11 FOM 12 FOP LENS
E
FOCUS SEARCH TRIANGULAR WAVE GENERATOR
Fig. 1.2.1 Block diagram of the focus servo system
F
CX-3026/E
7 7 8
5
6
1
2
3
4
A
Search start
Output from FD terminal
A blind period
The broken line in the figure is assumed in the case without focus servo.
FE controlling signals
B
You can ignore this for blind periods. FSS bit of SRVSTS1 resistor
RFOK signals The status of focus close is judged from the statuses of FSS and RFOK after about 10mS.
C
Fig. 1.2.2 Timing chart for focus close operations
1.2.2 Tracking servo system
In the tracking servo system, the digital equalizer block is used as its main equalizer. The figure 1.2.3 shows the block diagram of the tracking servo system. (a) Track jump Track jump operation is automatically performed by the auto-sequence function inside the LSI with a command from the microcomputer. In the search mode, the following five track jump modes are available: 1, 4, 10, 32, and 32*3 In the test mode, 1, 32, and 32*3 track jump modes, and carriage move mode are available and can be switched by selecting the mode. For track jumps, first, the microcomputer sets about half the number of tracks to be jumped as the target. (Ex. For 10 track jumps, it should be 5 or so.) Using the TEC signal, the microcomputer counts up tracks. When the counter reaches the target set by the microcomputer, a brake pulse is sent out to stop the lens. The pulse width is determined by the microcomputer. Then, the system closes the tracking loop and proceeds to the normal play. At this moment, to make it easier to close the tracking loop, the brake circuit is kept ON for 50msec after the brake pulse, and the tracking servo gain is increased. In the normal operation mode, the FF/REW operation is realized by continuously repeating single jumps about 10 times faster than the normal single jump operation. (b) Brake circuit The brake circuit stabilizes the servo-loop close operation even under poor conditions, especially in the setting-up mode or track jump mode. This circuit detects the lens-moving direction and emits only the drive signal for the opposite direction to slow down the lens. Thus, this makes it easier to close the tracking servo loop. The off-track direction is detected from the phases of the TEC and MIRR signals.
D
E
F
8 1 2
CX-3026/E
3
4
5
6
7
8
A
UPD63712GC E F BA5996FP
87 86
TE AMP
A/D
DIG. EQ CONTROL PWM TD 54 3 14 TOM 13 TOP LENS
JUMP PARAMETERS
B
Fig. 1.2.3 Block diagram of the tracking servo system
BRAKE TD
t2 t1
KICK
C
TEC
ON T. BRAKE OFF GAIN UP EQUALIZER GAIN NORMAL NORMAL OPEN T. SERVO CLOSED
D
Fig. 1.2.4 Single-track jump
E
F
CX-3026/E
9 7 8
5
6
1
2
3
4
A
TD
t1 t2
TEC (10 TRACK) GAIN UP EQUALIZER
50mS
NORMAL ON
T. BRAKE
B
SERVO
OFF OPEN CLOSED
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
D
TZC (TEC "SQUARED UP" ) (INTERNAL SIGNAL )
MIRR
MIRR LATCHED AT TZC EDGES SWITCHING PULSE =
E
EQUALIZER OUTPUT (SWITCHED)
DRIVE DIRECTION
REVERSE
FORWARD
Time
Note : Equalizer output assumed to hava same phase as TEC.
F
Fig. 1.2.6 Track brake
10 1 2
CX-3026/E
3
4
5
6
7
8
1.2.3 Carriage servo system
In the carriage servo system, the low frequency component from the tracking equalizer (the information on the lens position) is transferred to the carriage equalizer, where the gain is increased to a certain level, and then sent out from the LSI as the carriage drive signal. This signal is applied to the carriage motor via the driver IC. During the play mode, when the lens offset reaches a certain level, it is necessary to move the pickup toward the FORWARD direction. The equalizer gain is adjusted so that the output over the carriage motor starting voltage is sent out in such a case. In actual operations, only when the equalizer output exceeds the threshold level preset in the servo LSI, the drive signal is sent out. This can reduce the consumption power. With an eccentric disc loaded, before the whole pickup starts moving, the equalizer output may exceed the threshold level a few times. In this case, the drive signal applied from the LSI shows pulse-like waveforms.
A
B
UPD63712GC BA5996FP
From TRACK EQ.
DIG. EQ CONTROL PWM SD 56 24 17 LCOM CARRIAGE MOTOR 18 LCOP M
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 UPD63711GC)
E
CRG MOTOR VOLTAGE CARRIAGE MOVED AT THESE POINTS
Fig. 1.2.8 Waveforms of the carriage signal
F
CX-3026/E
11 7 8
5
6
1
2
3
4
A
1.2.4 Spindle servo system
In the spindle servo system, the following six modes are available: 1) Kick Used to accelerate the disc rotation in the setting-up mode. 2) Offset a. Used in the setting-up mode until the AGC completes after the kick mode. b. Used when the focus loop is unlocked during the play mode and until it is locked again. In both cases, the mode is to keep the disc rotation near to the appropriate one. 3) Applicable servo In the normal operation, the CLV servo mode is used. The EFM demodulation block detects through WFCK/16 sampling whether or not the frame sync signal and the internal frame counter output are synchronized, and generates the status signal based on the sampling result, synchronized or non-synchronized. If eight consecutive "non-sync" signals are obtained, the system senses the status as "nonsync". If not, the system senses as "sync". In the applicable servo mode, the leading-in servo mode is automatically selected at the non-sync status, and the normal servo mode is at the sync 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 moment, the EFM waveform is being monitored in this LSI. When the longest EFM pattern exceeds a certain cycle (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 keeps this for a certain period. In the eject mode, after the mode is shifted to the stop mode and a certain period passes, the loaded disc is ejected. 5) Stop Used when the power is turned on and during the eject mode. At this moment, the voltage through the spindle motor is 0V. 6) Rough servo Used when the carriage is moved (or in the carriage move mode such as long search). By obtaining the linear velocity from the EFM waveform, "H" or "L" is applied to the spindle equalizer. In the test mode, this mode is used for grating confirmation.
B
C
D
UPD63712GC
BA5996FP
SPEED ERROR SIGNAL 16 SOP 26 15 SOM SPINDLE MOTOR M
EFM SIGNAL
DSP BLOCK
DIG. EQ
PWM
MD 58
E
PHASE ERROR SIGNAL
Fig.1.2.9 Block diagram of the spindle servo system
F
12 1 2
CX-3026/E
3
4
5
6
7
8
1.3 AUTOMATIC ADJUSTMENT FUNCTION
This system automatically handles the circuit adjustment inside the CD LSI. All adjustments are performed whenever a disc is inserted or the CD mode is selected by pressing the source key. Each adjustment will be explained below.
A
1.3.1 TE, FE, and RF offset auto-adjustment
This adjustment is made to adjust the offsets of the TE, FE, and RF amplifiers in the preamplifier block to their target values on the basis of the REFO when the power is turned on. (The target values for TE, FE, and RE offsets are 0V, 0V, and -0.8V respectively.) 1) With the LD OFF status, the external microcomputer reads each offset through the servo LSI. 2) The microcomputer calculates the voltages for correction from the measured values, and inputs the calculated results as the offset adjustment values.
B
1.3.2 Tracking balance (T.BAL) auto-adjustment
This adjustment is to equalize the pickup output offsets for E-ch and F-ch by changing the amplifier gain inside the LSI. Actually, the gain is adjusted so that the TE waveform becomes symmetrical on each side of the REFO. 1) The focus loop is closed. 2) The lens is kicked in the radial direction to make certain that the TE waveform is generated. 3) The microcomputer reads the TE offset calculated in the LSI through the servo LSI. 4) The microcomputer takes either of the following steps depending on the calculated offset: · When the offset is 0, the adjustment completes. · When the offset is positive or negative, the amp gains for E-ch and F-ch should be changed. The steps 2) to 4) are repeatedly taken until the offset becomes 0 or the repeating time reaches the limit frequency.
C
1.3.3 EF bias auto-adjustment
This adjustment obtains the best focus point during the play mode and maximizes the RFI level by utilizing the phase difference between the 3T level of the RF signal and that of the signal obtained when focus error disturbance is applied to the focus loop. At this moment, the auto-gain control (AGC), where focus error disturbance is applied to the focus and tracking loops, is also performed as explained below. 1) The external microcomputer transmits the command to apply disturbance component to the focus loop (inside the servo LSI). 2) In the LSI, the 3T-offset component of the RF signal is detected. 3) From the relation between the 3T detected component and the disturbance, the LSI obtains the volume and direction of the focus offset. 4) The microcomputer transmits the command and reads out the detecting result from the servo LSI. 5) The external microcomputer calculates the necessary correction and inputs the result as the bias adjustment value to the servo LSI. The adjusting steps are repeated a few times for higher adjustment accuracy as same as those for the AGC.
D
E
1.3.4 Focus and tracking AGC
This function automatically adjusts the focus and tracking servo loop gains. 1) Disturbance component is applied to the servo loop. 2) The error signals (FE and TE) are extracted through the band pass filter as 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 higher adjustment accuracy, the above steps are repeated a few times.
F
CX-3026/E
13 7 8
5
6
1
2
3
4
A
1.3.5 RF level auto-adjustment (RFAGC)
This adjustment minimizes the dispersion of the RF level (RFO), which may be caused by disc-related errors, for more stable signal transmission by changing the amp gain between RFI and RFO. 1) The external microcomputer sends the command to the servo LSI to read out the output from the RF level detecting circuit inside the servo LSI. 2) The external microcomputer calculates the appropriate amp gain by using the output read out to adjust the RFO level at the prescribed one. 3) The external microcomputer sends the command to the servo LSI to adjust the amp gain into the calculated one. This adjustment is automatically performed when: 1) During the setting-up mode, only the focus close operation ends. 2) Immediately before the setting-up ends (or right before the play mode starts) 3) During the play mode, the focus loop is locked again after unlocked.
B
1.3.6 Pre-amp gain adjustment
In this adjustment, when the reflected beams from disc surface are extremely weak (ex. when the lens is dirty, and a CD-RW is loaded), the whole gain in the RFAMP block (FE, TE, and RF amplifiers) is increased by +6dB or +12dB. When the system senses that the reflected beams from disc surface are extremely weak during the setting-up mode, the whole RFAMP gain is increased by +6dB or +12dB. After the gain is changed, the setting-up mode is restarted. If the whole RFAMP gain is always increased to the +6dB level in the play mode, the +6dB level will be employed at the starting of the setting-up mode from the next playback.
C
Gain of entire RFAMP Play the CD-RW with the gain being set to +12dB
D
+ 12dB
+ 6dB
yy y ;;
Play is started with +6dB judging the lens is stained
E
TYP
Play at +6dB increases due to stained lens or other reasons (the typical gain is employed for the initial setup)
Time
Fig.1.3.1 Pre-amp gain adjustment
F
14 1 2
CX-3026/E
3
4
5
6
7
8
1.3.7 Initial values in adjustment
For each auto-adjustment, the last adjustment results are basically used as the initial settings of the next adjustment unless the external microcomputer is turned off (or the backup is off). When the microcomputer (or the backup) is turned off, the last adjustment results are not used, but the factory settings.
A
1.3.8 Adjustment result display
For some of the adjustments (FE and RF offset, FZD cancel, F and T gain, and RFAGC), the adjustment results can be displayed and confirmed in the test mode. 1) FE and RF offset Reference coefficient = 32 ("32" indicates no adjustment required) The display is expressed in the unit of about 32mV. Ex. When the FE offset coefficient is 35: 35 - 32 = 3 x 32mV = 96mV This means that the correction is about +96mV, and the FE offset before adjustment is -96mV. 2) F and T gain adjustment Reference coefficient for focus and tracking = 20 The displayed coefficient / the reference coefficient indicates the adjusted gain. Ex. When the AGC coefficient is 40: 40/20 = 2 times (+6dB) That is, the gain was adjusted by +6dB. (The original loop gain was half the target one. So, the whole gain was doubled.) 3) RF level adjustment (RFAGC) Reference coefficient = 8 The coefficient 9 to 15 indicates increasing the RF level. The coefficient 0 to 7 indicates decreasing the RF level. When the coefficient display changes by 1, the gain changes by 0.7 to 1dB. When the coefficient is 15, the gain is maximum or TYP + 6.5dB. When the coefficient is 0, the gain is minimum or TYP - 6.0dB.
B
C
D
E
F
CX-3026/E
15 7 8
5
6
1
2
3
4
A
1.4 POWER SUPPLY AND LOADING BLOCK
For the power supply for the internal system, the VD (8.3 + 0.5V) supplied from the mother P.C. Board is used. There are two power supply lines in the system: the VD for the drives and the V+3A for the controls obtained via the 3.3V regulator (3.3V). For all ON/OFF operations except for the CD driver's loading and ejection switching, the main unit's microcomputer controls with the CONT signal. For the loading drive ON/OFF operations, any control terminal is not prepared, but the LOEJ input functions like a control signal, instead. The LCO output section switches the mechanism between the loading and carriage modes with the CLCONT.
B
CD CORE UNIT(S10) MAIN UNIT
S902 S904
C
1 S905 2 48 6 11 VD DSCSNS CLAMP 10 IC301 19 BA5996FP 21 22 9 18 20 LCOM LCOP 28 S903
20 MICRO COMPUTER 11 12 14
3 5 7
CLCONT LOEJ CONT
M
LOADING MOTOR
D
30 20 21 PGND
17
Fig. 1.4.1 Power supply/loading block (*: CXK5600)
E
CLCLONT
Loading Mode
Carriage Mode
Loading Mode
F
Fig. 1.4.2 Loading/carriage mode shift
16 1 2
CX-3026/E
3
4
5
6
7
8
The load and eject operations are controlled by observing the status of the clamp switch on the mechanism unit and the three switches on the control unit. The DSCSNS voltage varies depending on the ON/OFF status of the switches. The main unit's microcomputer senses the status (A to E) by observing the voltage at the A/D port. Disc sense (8 or 12cm) is possible by utilizing this status change. The figures 1.4.3 and 1.4.4 show each status and change of the status respectively.
A
Status SW1(S903) SW2(S905) SW3(S904) SW4(S902) Mechanism state
A ON OFF OFF OFF With no disk
B OFF OFF OFF OFF
C OFF ON OFF OFF
D OFF ON ON OFF
E ON OFF OFF ON Clamp state
B
Fig.1.4.3 DSCSNS status
C
D
E
F
CX-3026/E
17 7 8
5
6
1
2
3
4
A
· LOADING
12cm STATE E B A C D A/D A B C D C B E SW_ON 12EJ SW CHANGES SW_OFF DSCSNS signal
B
8EJ
DSCSNS
CLAMP
CLCONT
C
CONTROL
LOEJ
MOTOR
STOP
LOAD
STOP
It changes Load/Cariage. 8cm STATE E B A C D A/D A B C B A or B B E DSCSNS signal
D
12EJ SW CHANGES
8EJ
DSCSNS
E
CLAMP
CLCONT CONTROL
LOEJ
MOTOR
STOP
LOAD Dead zone
STOP
F
18 1 2
CX-3026/E
3
4
5
6
7
8
A
· EJECT
12cm STATE E B A C D A/D E B C D C DSCSNS signal
B
12EJ SW CHANGES
8EJ
DSCSNS
CLAMP
CLCONT CONTROL
C
LOEJ
MOTOR
STOP
EJECT
STOP
8cm STATE E B A C D A/D E B A or B B C B DSCSNS signal
D
12EJ SW CHANGES
8EJ
DSCSNS
E
CLAMP
CLCONT CONTROL
LOEJ
MOTOR
STOP
EJECT Dead zone
STOP
F
Fig.1.4.4 Status change in LOAD and EJECT modes
CX-3026/E
19 7 8
5
6
1
2
3
4
A
2. MECHANISM DESCRIPTIONS
- Loading actions
1. When a disk is inserted, SW Arm L and R rotate. Due to the rotation of Arm L, SW1 is switched from ON to OFF and the Load Carriage Motor starts. 2. If the disk is 12cm-disk, when it is carried to the position shown with the dotted line in the drawing, SW 3 switches to ON due to such rotation of Arm. Then, the microcomputer judges that the disk is 12cm-disk. 3. In case of 8cm-disk, the disk cannot reach such dotted line position, and from such limitation of approach, the microcomputer judges that the disk is 8cm-disk and simply triggers clamp actions. (Movement of SW Arm L and R are connected together. So, if pushing force is fed to only one arm, the distance between tow arms cannot be widened beyond the specific degree, because the coupling part is locked in such case.)
Load Carriage Motor Pickup
B
SW3
C
SW2
Home SW
SW1 SW Arm L SW Arm R Mechanism Unit Lock Arm
D
- Disk centering mechanism
1. In case of 12cm-disk, the 12cm-Disk Detection Arm rotates, and with such rotation, it raises the Centering Arms to retreat the arms from disk's trace. The disk passes through under the arms, and at the inner part, it is centered. 2. In case of 8cm-disk, it is just centered at the position where its edge touches the front portion of the Centering Arm.
Centering Arm
E
12cm-Disk Detection Arm
12cm
Centering Arm
8cm
F
20 1 2
CX-3026/E
3
4
5
6
7
8
- Clamp actions
1. When an 8 or 12cm disc is placed on the center of the spindle, the detection arm starts moving. 2. The movement of the detection arm engages the loading rack with the 2-stage gear. 3. The clamp lever slides to lower the clamp arm. At this time, the roller up arm rotates to separate the roller arm from the disc. The roller arm moves the mech lock lever and turns the mech lock arm to release the mech lock. At the position where the clamp switch is turned off, the clamp operation ends. 4. After the clamp operation, the clamp lever moves to rotate the gear lock arm. The planet gear separates from the 2stage gear to get engaged with the pickup feed screw's gear. Then the carriage operation will start.
Feed Screw's Gear Clamp Lever Detection Arm
1 3
A
B
Loading Rack
1
2
2-Stage Gear
1
7
6
Gear Lock Arm
C
4 4
5
Planet Gear Mech Lock Lever
Clamp SW Roller Up Arm Mech Lock Arm Roller Arm
- Eject actions
1. Eject actions start when the Pickup is fed to the position inner than "Home SW ON" point in the internal circumference of the circle, caused by backward rotation of the Load Carriage Motor. Eject actions follow the foregoing procedures (steps taken in loading, centering and clamping actions), but each action in those steps is performed in reversed manner. 2. In case of 12cm-disk, Eject is completed when SW3 completes its condition- transition of OFF ON OFF. 3. For 8cm-disk, Eject is completed when SW2 completes its condition-transition of OFF ON OFF.
D
E
F
CX-3026/E
21 7 8
5
6
1
2
3
4
3. DISASSEMBLY
A
- How to hold the Mechanism Unit
1. Hold the top and bottom frame. 2. Do not squeeze top frame's front portion too tight, because it is fragile.
B
Do not squeeze.
- Removing the Upper and Lower Frames
C
1. With a disc clamped, remove the four springs (A), the two springs (B), the two springs (C), and the four screws. 2. To remove the upper frame, open it on the fulcrum A. 3. While lifting the carriage mechanism, remove the three dampers. 4. With the frames removed, insert the connectors coming from the main unit and eject the disc. Caution: Before installing the carriage mechanism in the frames, be sure to apply some alcohol to the dampers and set the mechanism to the clamp mode. Carriage Mechanism
A C A
Upper Frame
A
A
D
B Damper Lower Frame B
A Damper Damper
C
- Removing the Guide Arm Assy
1. Remove the upper and lower frames and set the mechanism to the clamp mode. 2. Remove the two springs. 3. Remove the two screws and bevel gear bracket. Note that the gears come off. 4. Slide the guide arm assy in the direction marked with the arrow (1) and open it upwards. 5. At the angle of about 45 degrees, slide the guide Spring arm assy in the direction marked with the arrow (3) to remove it.
E
3 2 1
Guide Arm Assy
F
Spring
22 1 2
CX-3026/E
3
4
5
6
7
8
A
Bevel Gear Bracket
B
- Removing the CD Core Unit(S10)
1. Apply shorting solder to the Pickup flexible cable. Disconnect the cable. 2. Remove the solder from the four leads, and loosen the screw. 3. Remove the CD core unit(S10). Caution: When assembling the CD core unit(S10), set Shorting Solder the mechanism to the clamp mode to protect the switches from any damage.
C
Solder
D
CD Core Unit(S10)
- Removing the Roller Arm Assy
1. Remove the guide arm assy and set the mechanism to the eject mode. 2. Remove the CD core unit(S10). (You do not have to remove the solder from the four leads.) 3. Remove the spring and E-shaped ring from the fulcrum shaft. 4. Slide the roller arm assy in the direction marked with an arrow.
E
Roller Arm Assy
F
E-Shaped Ring
CX-3026/E
23 7 8
5
6
1
2
3
4
A
- Removing the Pickup Unit
1. Set the mechanism to the clamp mode. 2. Remove the lead wires from the inner holder. 3. Remove the two washers, styling holder, change arm, and pickup lock arm. 4. While releasing from the hook of the inner holder, lift the end of the feed screw. Caution: In assembling, move the planet gear to the load/eject position before setting the feed screw in the inner holder.
Washer Pickup Lock Arm Styling Holder Feed Screw Change Arm
B
Inner Holder
C
Planet Gear
- Removing the Load Carriage Motor Assy
1. Release the leads from the styling holder and remove the holder. 2. Remove the two screws. 3. Remove the load carriage motor assy. Styling Holder Load Carriage Motor Assy
D
E
F
24 1 2
CX-3026/E
3
4
5
6
7
8
- Removing the Clamp Arm Assy
1. Remove the five springs. 2. While lifting the clamp arm assy, slide it in the direction marked with the arrow (2) to remove it. Spring
1 2
A
Spring Clamp Arm Assy
Spring
B
Spring Spring
- Removing the Spindle Motor
1. Remove the two screws. Take off the spindle motor.
C
Spindle Motor
D
E
F
CX-3026/E
25 7 8
5
6