TABLE OF CONTENTS
1. SERVICE NOTE.................................................................6. EXPLODED VIEWS3
6-1. Cabinet Section ................................................................. 20
2. GENERAL............................................................................6-2. MD Section.......................................................................422
3. DISASSEMBLY7. ELECTRICAL PARTS LIST.........................................23
3-1. Cabinet (Rear) Sub Assy ..................................................... 5
3-2. Main Board ......................................................................... 5
3-3. MD Assy ............................................................................. 5
4. ELECTRICAL ADJUSTMENTS...................................6
5. DIAGRAMS
5-1. IC Pin Descriptions ............................................................. 7
5-2. Block Diagram .................................................................... 9
5-3. Printed Wiring Board ........................................................ 12
5-4. Schematic Diagram �Main Section (1/2)� ........................ 15
5-5. Schematic Diagram �Main Section (2/2)� ........................ 17
SECTION 1
SERVICE NOTE
NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK ORLaser Diode Checking Methods
BASE UNITDuring normal operation of the equipment, emission of the laser
The laser diode in the optical pick-up block may sufdiode is prohibited unless the upper lid is closed while turning ONfer electrostatic
breakdown because of the potential difference generathe S808 (push switch type).ted by the
charged electrostatic load, etc. on clothing and the human bodyThe following chec.king method for the laser diode are operable.
During repair, pay attention to electrostatic breakdown and also use
the procedure in the printed matter which is included in the repairEmission of the laser diode is visually checked
parts.1. Open the upper lid.
The flexible board is easily damaged and should be handled with2. Push the S808 as shown in Fig. 1.
care.3. Check the objective lens for confirming normal emission of
the laser diode. If not emitting, there is a trouble in the
NOTES ON LASER DIODE EMISSION CHECKautomatic power control circuit or the optical pick-up.
The laser beam on this model is concentrated so as to be focused onDuring normal operation, the laser diode is turned ON about
the disc reflective surface by the objective lens in the optical pick-up2.5 seconds for focus searching.
block. Therefore, when checking the laser diode emission, observe
from more than 30 cm away from the objective lens.
Before Replacing the Optical Pick-Up Block
Please be sure to check throughly the parameters as par the OOptical
Pick-Up Block Checking Procedures� (Part No.: 9-960-027-11)S808
issued separately before replacing the optical pick-up block.
Note and specifications required to check are given below.
Y FOK output : IC501 @° pin
When checking FOK, remove the lead wire to disc motor.
Y S curve P-to-P value : 2.0Vp-p IC501 $Y pin
When checking S curve P-to-P value, remove the lead wire to
disc motor.
Y RF signal P-to-P value : 0.6 - 1.3Vp-p
Y Traverse signal P-to-P value : 0.8 - 2.8Vp-p
Y The repairing grating holder is impossible.
Precautions for Checking Emission of Laser Diode
Laser light of the equipment is focused by the objective lens in the
optical pick-up so that the light focuses on the reflection surface of
the disc.
Therefore, be sure to keep your eyes more than 30 cm apart fromFig. 1 Method to push the S808
the objective lens when you check the emission of laser diode.
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ACEC
