User manual SONY CDP-C900

[. . . ] These 200 series models are mechanically complex so there are more CD transport and mechanical adjustments to be made. The concepts and circuitry in this 200 disc model are similar to the 300 disc CDP-CX300 series and 400 disc CDP-CX400 series CD Changers. In these larger capacity models, the CD transport and CD mechanism use fewer parts. As a result, the higher capacity Changers require fewer adjustments. [. . . ] The second mode comes some time later after the tracking servo operates. This is when the RFO data is reliable and can be used to govern the spindle motor speed. This second mode of operation cannot be seen because the motor is already running. However when the motor is linked to the disc data, the LOCK test point goes HIGH. Tracking Servo Once focus is found (FOK goes HIGH), the spindle motor starts and the tracking servo loop is closed. The tracking servo moves the objective lens so the laser can follow the disc's information track. The center of the disc's track is identified using optical assembly detectors E & F. The RF Amp converts these two input signals into a tracking error (TE) correction signal that is sent to Servo Control. Servo control amplifies the TE input and closes the servo loop switch, outputting the amplified tracking error signal (TEO). Servo Control TEO RFO, FE TE test point TE Driver Optical Assembly Lock Spindle Servo Control LPF Driver M FE RFO RF Amp A-D detectors Optical Assembly E, F Audio Block RF Amp The driver IC that receives TEO supplies current to generate a magnetic field in the tracking coil. The coil moves the objective lens (with laser beam) so the beam follows (tracks) the disc data. Once the spindle motor is locked to the data (LOCK = HIGH), the data is reliable enough to be audio processed. The disc data comes into Servo Control as RFO. It is error corrected, digitally reconstructed and output as a digital signal to the rear panel jack. This servo results in a periodic track correction signal that looks like about 400mV of noise at the TE test point. 339 , U & S ch1: pkpk= 1. 44 V ch1 Defective Tracking Servo Waveforms Channel Signal Name Location 1 RFO test point IC103/pin 16 2 TE test point IC103/pin 13 Time base = 100msec/div Scope ground is taken at Vc (IC103/pin 12) ch2 Spindle Servo 1 Although the spindle motor has started when focus was found (FOK = HIGH), its lock onto the data does not occur until about 800msec later. At that time the LOCK signal goes HIGH. PM3394, FLUKE & PHILIPS ch1 T ch2 1 2 CH1 1. 00 V= CH2!200mV= STOP MTB1. 00ms PKD ch1+ ch3 2 ch4 Normal CD Playback Channel Signal Name Location 1 RFO test point IC103/pin 16 2 TE test point IC103/pin 13 Time base = 1msec/div Scope ground is taken at Vc (IC103/pin 12) When the tracking loop is open, the laser is no longer following the data track. In the following scope shot, the RFO waveform in channel 1 shows the laser is seeing alternate areas of RF data (teeth) and no data (gaps). Channel 2 shows there is TE correction signal generated from IC103/pin 13, but it is not reaching the tracking coil for correction. PM3394, FLUKE & PHILIPS ch1: ch1 pkpk= 1. 28 V 3 CH1 2. 00 V= CH2!5. 00 V= 4 CH3!5. 00 V= CH4!5. 00 V= CHP MTB 200ms- 2. 28dv ch1+ Channel 1 2 3 4 ch2 CD Playback Starting Signal Name Location RFO IC103/pin 16 FOK test point IC101/pin 24 LOCK test point IC101/pin 25 C2PO test point IC101/pin 19 Time base = 200msec/div Scope ground is taken at Vc (IC103/pin 12) 1 At this time, the RFO signal should be at least 1Vp-p (1. 2Vp-p = normal) and the RFO waveform should be straight on top and bottom (no dropouts). Once the LOCK test point goes HIGH, the servos are all working and audio should output if that processing within IC101 is OK. ch1+ 2 CH1 1. 00 V= CH2!500mV= STOP MTB1. 00ms PKD D+5V VCC 2 VCC 1 OPTICAL PICKUP KSS-213B FOCUS COIL RIBBON CABLE CONNECTOR CN102 13, 16 5V 2. 5V DETECTOR OUTPUTS 38 10 24 12 VCC VC IC103 RF AMP CXA2568M A-F 3 LD PD 14 13 TRACK COIL 14, 15 Q101 12 4 L D ON 22 16 FE R103 FOCUS, TRACK SLED DRIVE 39 41 TE R101 14 43 RFO RFDC 59 10 72 75 60 1 FE TE +7V 21 22 VCC VCC IC102 DRIVER BA6382FP LD ON RF D+5V L OUT 1 L OUT 2 D OUT SQS SQCK L, R CH AUDIO OUT DIG OUT SUB Q DATA CLOCK TO SYSCON IC501 MDP LPF X101 16. 93MHz R105 26 67 IC101 DSP, CLV SERVO, CXD2587 Q 8 66 27 6 7 5 19 25 24 2 M M HOME S101 D+5V 49 XLT CLK 48 50 C2PO LOCK FOK DATA SPINDLE SLED IC501SYSCON (MAIN BD. ) 10A122 1249 6 28 2000 SERVO PROCESSING 38 39 Audio / Display Output Analog Audio Output The left and right channels of Servo Control IC101 are applied to amplifier IC401. Their outputs are AC coupled to the rear panel phono jacks. The following signal levels were measured using the Sony YEDS-18 test disc track #5 (10kHz mono, 0db). IC401 voltages Measurement Pin 2 Pin 3 DC 0V 0V AC 3Vp-p 3Vp-p Pin 1 0V 5Vp-p When a disc is played, the base frequency square wave is replaced with data. T 1 Digital Output Signal Power ON, Disc PB Name Location Frequency Digital Output CN502/pin 10 (from data (electrical) IC101/pin 60) Time base = 0. 5usec/div Muting transistors Q325, Q327, and Q425 mute the output audio at power ON and OFF. Display SQ data and clock from Servo Control IC101/pins 1 and 2 are applied to Syscon IC501 for processing. The results of this data will be the CD time, track, and name information applied to the FL display driver IC701. The SQ data and clock are only present when a disc is played. PM3394, FLUKE & PHILIPS ch1 Digital Output The digital output signal from Servo Control IC101/pin 60 is applied to IC901 at the rear panel of the changer. [. . . ] (Compares VCO to crystal. ) On/Off control for the CLV spindle servo Mutes the audio output. The input/output of the PLL phase detector/comparator. viii SFDR SFON SRDR SRON Sled Forward DRive Sled Forward ON Sled Reverse DRive Sled Reverse ON The output of any of the detectors in the pick-up assembly. 4. 32 MHz clock divided from the phase locked VCO. Used as the bit clock to process and write data before RAM. [. . . ]