SECTION 2
SERVICE NOTE
NOTES ON HANDLING THE OPTICAL PICK-UPPrecautions for Checking Emission of Laser Diode
BLOCK OR BASE UNITLaser light of the equipment is focused by the object lens in the
optical pick-up so that the light focuses on the reflection surface of
The laser diode in the optical pick-up block may suffer electrostatic
breakdown because of the potential difference generated by thethe disc. Therefore, be sure to keep your eyes more then 30 cm
charged electrostatic load, etc. on clothing and the human body.apart from the object lens when you check the emission of laser
During repair, pay attention to electrostatic breakdown and also usediode.
the procedure in the printed matter which is included in the repair
parts.Laser Diode Checking Methods
The flexible board is easily damaged and should be handled with
care.During normal operation of the equipment, emission of the laser
diode is prohibited unless the upper panel is closed while turning
ON the S801 (push switch type).
NOTES ON LASER DIODE EMISSION CHECKThe following two checking methods for the laser diode are operable.
The laser beam on this model is concentrated so as to be focused onY Method (In the service mode or normal operation):
the disc reflective surface by the objective lens in the optical pick-Emission of the laser diode is visually checked.
up block. Therefore, when checking the laser diode emission,1. Open the upper lid.
observe from more than 30 cm away from the objective lens.
2. Push the S801 as shown in Fig. 1.
Before Replacing the Optical Pick-Up Block3. Check the object lens for confirming normal emission of the
laser diode. If not emitting, there is a trouble in the automatic
Please be sure to check thoroughly the parameters as par the OOpticalpower control circuit or the optical pick-up.
Pick-Up Block Checking Procedures� (Part No.:9-960-027-11)During normal operation, the laser diode is turned ON about
2.5 seconds for focus searching.
issued separately before replacing the optical pick-up block.
Note and specifications required to check are given below.
Y FOK output: IC501!a pin
When checking FOK, remove the lead wire to disk motor.
Y S curve P-to-P value: 1.0-2.8Vp-p IC501#�pin
When checking S curve P-to-P value, remove the lead wire to
disc motor.
Y RF signal P-to-P value: 0.8-1.2Vp-p
Y Traverse signal P-to-P value: 1.2Vp-p
Y The repairing grating holder is impossible.
Fug. 1 Method to push the S801
N 7 N |