Pioneer-CX893-tape-cdm 电路图 维修手册.pdf

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1、PIONEER ELECTRONIC CORPORATION4-1, Meguro 1-Chome, Meguro-ku, Tokyo 153-8654, Japan PIONEER ELECTRONICS SERVICE INC.P.O.Box 1760, Long Beach, CA 90801-1760 U.S.A. PIONEER ELECTRONIC EUROPE N.V.Haven 1087 Keetberglaan 1, 9120 Melsele, Belgium PIONEER ELECTRONICS ASIACENTRE PTE.LTD.501 Orchard Road, #

2、10-00, Wheelock Place, Singapore 238880 C PIONEER ELECTRONIC CORPORATION 1998 K-ZZB. OCT. 1998 Printed in Japan ORDER NO. CRT2291 MD MECHANISM MODULE CX-893 Service Manual CONTENTS 1. CIRCUIT DESCRIPTIONS.2 2. DISASSEMBLY.13 - This service manual outlines operations of the MD mechanism module used i

3、n the models listed below. - For repair, use this Service Manual and the Service Manual of the model used in the system. ModelService manualMD mechanism module MEH-P5000R/EWCRT2287CXB2784 RadioFans.CN 收音机爱 好者资料库 Figure 1 below shows the block diagram. This block controls the output from the block LD

4、 to be consistent with the monitor diode. The block consists of IC 102 and turned to LD ON when LDON (6 pin) is H and to LD OFF when LDON is L. LD output level is set with the voltage value of LDVAR and is usually around 2.4 V. 2 CX-893 1. CIRCUIT DESCRIPTION 1.1 APC Part Fig.1 1.2 RF amplifying par

5、t The block amplifies the pickup output signal and generates RF and ADIP signals. This block mainly consists of IC101. REFO part REFO (+1.5 V) is the reference voltage for the servo. The signal is resistive divided at the IC (REFI: 5 pin) and output to 6 pin through buffer. This signal will be the r

6、eference for RFIC. RF signal amplifying part Figure 2 below shows the block diagram. The signal which is I-V converted at the pickup is input to the RF1-4 (1-4 pin). Gain at the I-V amplifier contained in the PU is switched depending on the disc types. The switching is controlled by OPICGA (IC401, 6

7、1 pin) and H is output at Premaster DISC and L is output at Recordable DISC. The signal input from the I-V amplifier is operated with the contained resistance and amplifiers (A1, A2) and the signal (RF1 + RF2 + RF3 + RF4) (POUT) and the signal (RF1 + RF2 + RF3 - RF4) (GOUT) are generated. Each of PO

8、UT and GOUT is equipped with an analog switch. The switches are controlled with the DISC signal (bits on microprocessor serial communications). The POUT signal is output through 48 pin when the DISC signal is H (PIT mode) and GOUT signal is output through 47 pin when the DISC signal is L (GRV mode).

9、 These signals are input to EFMAGC (45 pin) through the coupling capacitors (C133, C112) and transmitted to the AGC circuit and filter part to be output from EFMO (40 pin). The EFMO is maintained at almost same level (approx. 1.5 Vpp) with the AGC circuit. These signals are input to the signal proce

10、ssing part (IC201: 3 pin) and used for data processing and spindle control when playing a Premaster Disc. RadioFans.CN 收音机爱 好者资料库 3 CX-893 Fig.2 ADIP signal amplifying part Figure 3 shows the block diagram of this part. The block generates the ADIP signal which exists only on a Recordable DISC of a

11、MD. Signals input to RF1 and RF2 (1,2 pin) are transmitted through the AGC part and the filter part to be output to 22KO (32 pin). The 22KO is designed to be maintained at almost same level (approx. 1.2 Vpp) with the AGC circuit. However, fluctuation of about +0.5V may be observed due to core compon

12、ents, responsibility of tracking servo, etc. The signal is then converted to 1 and 0 signal with the comparator C1, input to the signal processing part (IC201:11 pin), and used for address control when playing disc for recording and spindle control. *Will not be used when Premaster Disc is played. C

13、1 Fig.3 RadioFans.CN 收音机爱 好者资料库 4 CX-893 Track cross part, signal amplifying part for servo Figure 4 shows the block diagram of these parts. The signal input to RF1-4 (1-4 pin) is resistive divided and amplified to be output to TCGO (29 pin). TCGO is input to the signal processing part (IC201:7 pin)

14、 and TCRS signal is generated and will be used when the system skips tracks to play. Outputs from the focus servo based photo diode are input to AIN (9 pin) and BIN (10 pin) and are output to AOUT (28 pin) and BOUT (27 pin), respectively, after being amplified. Outputs from focus servo based photo d

15、iode are input to EIN (11 pin) and FIN (12 pin) and are output to EOUT (26 pin) and FOUT (25 pin), respectively, after being amplified . These signals are input to the signal processing part (IC201: 5,6,7,8,9 pin) and used at each servo. Amplifying ratios of each signal are controlled by the micropr

16、ocessor and adjusted so that they reach optimized values when mechanical modules are shipped. Those optimized values are stored in IC402. Therefore, when you replace IC or PU switch, etc., you should have the IC402 memorize new optimized values by turning EEPROM (IC402) to write mode (See the releva

17、nt sections for details.) and running test modes AUTO1 and AUTO2 with a Recordable DISC (MMD-211 or MMD-212). Fig.4 5 CX-893 Logic part Serial commands of the microprocessor determines the setting of this IC. Timing chart DATA (23pin) CLOCK (22pin) LATCH (21pin) MSB7SB6SB5SB4SB3SB2SB1SB Structure of

18、 serial data MSB7SB6SB5SB4SB3SB2SB1SB Pattern AHLFocus gainTracking gain Pattern BLHSTBYDISCSGAIN Track loss gain Gain setting (+12dB when SGAIN=H at normal operation) Setting valueFocus gainTracking gainTrack loss gain 000404018 001343412 01028286 01122220 10016166 101101012 1104418 1114418 STBY: S

19、witches to stand-by mode H: Normal L: Stand-by DISC: Switches to disc mode H: PIT (Premaster Disc) L: GRV (Recordable Disc) SGAIN: Switch of amplifier gain for servo H: +12dB L: Normal 6 CX-893 1.3 Signal processing part (IC201) This block consists of the following four parts: 1) Servo part 2) Signa

20、l processing part 3) Shock proof controlling part 4) ATRAC part The details for each part are described below. 1) Servo part 1.1) Focus servo Figure 5 shows the block diagram of the focus servo. The signals input to AIN (5 pin) and BIN (8 pin) are processed with subtraction treatment after analog- d

21、igital conversion. These signals can be monitored with FEMON (75 pin). These signals, however, should be monitored using LPF with cutoff of around 50 kHz (e.g. R=100 k, C=33 pF) because they are PWM signals. These signals are equalized at subsequent D and F parts and output to FODRF (18 pin) and FOD

22、RR (19 pin) with PWM. The output signals are amplified with the driver (IC601) and drive the actuator. You must move the lens up and down for close focus. Close the focus when the following requirements are met: 1) When the lens is going down. 2) FOK (82 pin) = L 3) FZC (signal inside IC ) = i Fig.5

23、 7 CX-893 1.2) Tracking servo and thread (carriage) servo Figure 6 shows the block diagram of the tracking servo and thread (carriage) servo. 1.2.1) Tracking servo Signals input to EIN (6 pin) and FIN (9 pin) are processed with subtraction treatment after analog- digital conversion. These signals ca

24、n be monitored with TEMON (75 pin). These signals, however, should be monitored using LPF with cutoff of around 50 kHz (e.g. R=100 k, C=33pF) because they are PWM signals. These signals are equalized at subsequent D and F parts and output to TRDRF (20 pin) and TRDRR (21 pin) with PWM. The output sig

25、nals are amplified with the driver (IC601) and drive the actuator. 1.2.2) Thread servo Thread servo extracts and amplifies only low frequency signals by transmitting the outputs from tracking D and F parts through D and F parts. When these signals exceed a certain threshold voltage, they are output

26、to SLDRF (22 pin) and SLDRR (23 pin) with PWM. These signals are amplified with the driver (IC601) and then drives the motor. Fig.6 1.3) Track jumping Tracks to play are automatically skipped using AUTO mode which is an LSI function. Figure 7, 8, and 9 show examples of 1TJUMP, 10JUMP and Auto MOVE,

27、respectively. 8 CX-893 Antiskid SLKLEV WAIT SLCT Automove Antiskid SENSE (terminal) Tracking output Tracking count (COUT) : the no. of tracks = TRCNT x 64 Thread output Specified no. of tracks Fig.7 Fig.8 Fig.9 TE Tracking drive output SENSE (terminal) TE Tracking drive output SENSE (terminal) 1.4)

28、Spindle servo Figure 10 shows the block diagram of the spindle servo. Perform CLV control with EFMI (3 pin) when you play the read-in area of a Premaster DISC or Recordable DISC and with WBI (11 pin) when you play the program area of a Recordable DISC. 1.5) Auto tuning This mechanical module is auto

29、matically tuned so that it absorbs dispersion among discs caused by ambient changes or course of time thereby stabilizing the play of discs. This auto tuning will be made whenever you insert a disc or select MD mode with the source cue. 1.5.1) When you play Premaster DISC Tracking ATT tuning Measure

30、s the levels of LPFEINO, LPFFINO and EFMIO that EIN (6 pin) and FIN (9 pin) generate and specifies the amount of ATT that is calculated with formula. u Maintains the tracking loop gain at a certain level and stabilizes the tracking servo operation. Focus ATT tuning Measures the levels of LPFABO that

31、 AIN (5 pin) and EIN (8 pin) generate and specifies the amount of ATT that is calculated with formula. u Maintains the focus loop gain at a certain level and stabilizes the tracking servo operation. 1.5.2) When you play a Recordable DISC Tracking ATT tuning (PIT. GRV) Measures the levels of LPFEINO,

32、 LPFFINO and EFMIO that EIN (6 pin) and FIN (9 pin) generate and specifies the amount of ATT that is calculated with formula. u Maintains the tracking loop gain at a certain level and stabilizes the stabilizes the tracking servo operation. Focus ATT tuning (PIT. GRV) Measures the levels of LPFABO th

33、at AIN (5 pin) and EIN (8 pin) generate and specifies the amount of ATT that is calculated with formula. u Maintains the focus loop gain at a certain level and stabilizes the tracking servo operation. TCRS ATT tuning Measures the level of TCGSMIO that TOG (7 pin) generates and specifies the amount o

34、f ATT that is calculated with formula. u Stabilizes searches when you play a Recordable DISC. 9 CX-893 Fig.10 2) Signal processing part Figure 11 shows the block diagram of signal processing, shock proof controlling and ATRAC parts. The signal processing part consists of the two blocks, one of which

35、 demodulates the music data on the disc and corrects errors, and the other of which controls addresses used for searches and time calculation. 2.1) Music data The signal input from EFMI (3 pin) is equalized with the digital filter after analog-digital conversion. This signal can be monitored with EF

36、MO (1 pin). The signal will be sliced at an appropriate level and modulated to 0 and 1 signal and then transmitted to the subsequent shock proof part after EFM demodulation and error correction are completed. 2.2) Address control Reads the address data on the disc and specifies targets for time cont

37、rol during play and searches. The methods of reading the address data depends on the disc types. When you use a Premaster DISC Extracts the address data from the music data after error correction is completed. When you use a Recordable DISC Modulates frequency of the signal input from WBI (11 pin) a

38、nd reads the addresses from the data. 3) Shock proof controlling part The data from the signal processing part is temporarily stored in DRAM (IC202). Later, the data will be sent out sequentially by the data requests from the subsequent ATRAC part or instructions from the microprocessor. This mechan

39、ical module contains the 4MB DRAM and can store the data of approximately 10 seconds. 4) ATRAC part The data from DRAM (IC202) will be extended for ATRAC at this block and then converted into the audio data. The data formats to be used at the subsequent DAC (IC501) are as follows: BCLK (71 pin): 64

40、Fs DADATA (74 pin): 20 bits from the last DFCK (72 pin): 256 Fs LRCK (70 pin): Fs, L/R *Fs=44.1 kHz 10 CX-893 Fig.11 1.4 Mechanical control 1) Loading The microprocessor instructs the motor driver IC651 to rotate backward (IC651: 3 pin: L, 4 pin:HtL+: L, L-:H) if LOAD STRAT SW (SW652) detects OFF (L

41、OAD STRAT=H). If LOAD STRAT SW (SW652) detects ON (LOAD END=L) later, the microprocessor instructs the motor driver IC651 to stop (IC651: 3pin: H, 4pin:HtL+: L, L-:H) and completes the loading and then transits to PLAY operation. If DISC IN SW (SW903) is OFF (DISC IN=H) or LOAD END SW has been OFF f

42、or a long time, the microprocessor determines that there is no inserted disc or a disc insertion error and performs EJECT or Error STOP. 2) EJECT The microprocessor instructs the motor driver IC651 to positively rotate (IC651: 3 pin: H, 4 pin:LtL+: H, L-:L) when it receives the EJECT instruction. If

43、 EJECT END SW (SW653) detects ON (EJECT END=L) later, the microprocessor instructs the motor driver IC651 to stop (IC651: 3pin: H, 4pin:HtL+: H, L-:H) and completes the EJECT operation. 11 CX-893 1.5 Others 1) Temperature detection This module detects high temperatures, to protect PU. When the tempe

44、rature of the output from the temperature sensor (IC402) exceeds a certain voltage level, it is determined as high temperature and an appropriate process such as Error STOP will be performed. The ambient temperature which causes that high temperature on the module is approximately 80 degree Celsius.

45、 2) Voltage monitoring This module monitors voltage to protect the system. The signals which are resistive divided (R803, 804) from the input VD from the product (CN301: 1,2) are monitored (IC401, 25 pin). If the voltage of the signal is higher than 2.86 V (VD7V or higher) or lower than 2.04 V (VD5V

46、 or lower), an appropriate process such as Error STOP will be performed. 12 CX-893 1.6 How to rewrite EEPROM This mechanical module stores adequate values for the servo, etc., in the EEPROM (IC402). Therefore you need to rewrite the data in the EEPROM when you replaced mechanism, PU, LSI, or micropr

47、ocessor. - When you replaced EEPROM (IC402), microprocessor (IC401) 1 Make TP435 (IC402: 6 pin) and TP421 (IC402: 8 pin) short-circuited. 2 Start the product in Test mode. (See manuals for each product for how to start.) 3 Display the EEPROM setting menu and view any setting value, e.g., Focus “FGP_

48、XX”. (You should not change the value.) 4 Switch to Test STOP mode. 5 Turn ACC off. * After turning ACC off, wait for about 10 seconds because EEPROM is written into during that time. 6 Turn Backup off. 7 Disconnect the short-circuits you have done in the step 1). - When you replace pickup, mechanis

49、m, LSI (IC101, 201) or their peripherals. 1 Make TP435 (IC402: 6 pin) and TP421 (IC402: 8 pin) short-circuited. 2 Start the product in Test mode. (See manuals for each product for how to start.) 3 Load Recordable DISC (MMD-211 or MMD-212) and run AUTO1. When “Complete” sign appears, press the FUNC key and run AUTO2. When “Complete” sign appears again, press the FUNC key and confirm the indicated addresses are normally counted up. *If “Cant ADJ” sign appears in this step, check the so