Sony CDP CX400 Service Manual
This is the 68 pages manual for Sony CDP CX400 Service Manual.
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Extracted text from Sony CDP CX400 Service Manual (Ocr-read)
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Sony Service Company A Division of Sony Electronics Inc ©2000 All Rights Reserved Printed in U.S.A. S is a trademark of Sony Electronics
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Circuit Description and Troubleshooting: Models: CDP-CX235 CDP-CX270 CDP-CX335 CDP-CX400 CDP-CX450 Prepared by: National Training Department Sony Service Company A Division of Sony Electronics Inc. Course presented by _____________________________________ Date ___________________________________________________ Student Name ___________________________________________
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3 Overall Block Diagram At the core of the 200 disc CD Changer is the System Control (Syscon) IC501. IC501 serves as the interface between the user and the mecha- nism. Before IC501 can respond to the users commands for a disc to play, it must know the following: · If the Disc door is closed. · If the CD Mechanism is in the chucked position. · At which disc slot is the tray table is positioned. Some of this information is stored in an external memory IC; the remain- der IC501 will have to gather at power ON using the sensors and switches linked to the Door, Tray Table and Loading Motors. Information Gathering Pressing the power ON button causes IC501 to use IC SW to switch on regulator IC506. IC506 apples power to the BD board, which houses the optical assembly. D+5V is also applied to the LED in the door compart- ment to inform the user power is ON. After Syscon IC501 turns on power, IC501 accesses its external memory IC. Data about the disc last loaded in the CD Mechanism is returned to IC501. The disc label information is output as data to the FL Display IC for display on the front panel fluorescent tube. If there was no label infor- mation, then just the discs number is displayed. Syscon now takes a series of steps to check the memory information: 1. Syscon activates the disc door motor to close the door if its corre- sponding switch indicates the door is open. 2. Next, Syscon checks the loading motor switch position to see if the CD Mechanism is in the chucked position (disc loaded). If chucked, IC501 will initiate disc PB to read its TOC. If unchucked, IC501 will drive the tray table motor, rotating its discs past the disc sensors. While the tray is rotating, the tray sensors inform IC501 of the disc slot location while the disc sensor tells IC501 if there is a disc present at that slot. The last disc played according to memory will be loaded and its TOC read (if present).Once Syscon IC501 is confident the tray table information is valid, IC501 turns the CD Changer control over to the user by accepting pushbutton commands. The user can use the front panel controls to select another disc or play that one. When Syscon knows the loading motor is in the chucked posi- tion (loading motor switch), the CD can be played. CD Playback Syscon IC501 initiates CD play by sending data, clock and latch commu- nications to IC101 on the BD board. This causes IC101 to turn on the laser, focus, tracking and spindle servos that employ the laser diode, along with the focus coil, tracking coil, sled motor and spindle motor in the opti- cal assembly. Once these servos are operating, the disc information (RFO) is output. RFO is received by Servo Control IC101 which: Converts the data back to the original modulation scheme (EFM). Error corrects the data (parity error correction). Reconstructs its original pattern (CIRC). Creates additional digital samples (oversampling) to reduce noise in the final analog audio. Converts the signal from digital to analog form (D/A Converter). Analog audio is output from IC101 to the rear panel jacks.