SECTION 1
SERVICING NOTES
Precautions for Checking Emission of Laser Diode
NOTES ON HANDLING THE OPTICAL PICK-UPLaser light of the equipment is focused by the object lens in the
BLOCK OR BASE UNIToptical pick-up so that the light focuses on the reflection surface
The laser diode in the optical pick-up block may suffer electro-of the disc. Therefore, be sure to keep your eyes more then 30 cm
static breakdown because of the potential difference generated byapart from the object lens when you check the emission of laser
the charged electrostatic load, etc. on clothing and the human body.diode.
During repair, pay attention to electrostatic breakdown and also
use the procedure in the printed matter which is included in theLaser Diode Checking Methods
repair parts.During normal operation of the equipment, emission of the laser
The flexible board is easily damaged and should be handled withdiode is prohibited unless the upper panel is closed while turning
care.ON the S801. (push switch type)
The following two checking methods for the laser diode are oper-
able.
Befor Replacing the Optical Pick-Up Block
Please be sure to check thoroughly the parameters as par the OOp-Y Method (In the service mode or normal operation):
tical Pick-Up Block Checking Procedures� (Part No.: 9-960-027-Emission of the laser diode is visually checked.
11) issued separately before replacing the optical pick-up block.1. Open the upper lid.
Note and specifications required to check are given below.
2. Push the S801 as shown in Fig. 1.
Y FOK output: IC501 !a pin3. Press the ^ key.
When checking FOK, remove the lead wire to disc motor.4. Check the object lens for confirming normal emission of the
Y S curve P-to-P value: 0.6 to 1.8 #� pinVp-p IC501 laser diode. If not emitting, there is a trouble in the automatic
When checking S curve P-to-P value, remove the lead wire topower control circuit or the optical pick-up.
disc motor.During normal operation, the laser diode is turned ON about
Y RF signal P-to-P value: 0.8 to 1.2 Vp-p2.5 seconds for focus searching.
Y Traverse signal P-to-P value: 1.2 Vp-p
Y The repairing grating holder is impossible.
S801
Fig. 1 Method to push the S801
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ACEC
