SECTION 1
SERVICING NOTES
5. Calculate the current value by the reading of the digital voltmeter.
NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK OR
Reading of the tester (V) � 4.7 ( W ) = current value (A)
BASE UNIT
(Example) Reading of the digital voltmeter of 0.2256 V :
The laser diode in the optical pick-up block may suffer electrostatic0.2256 V � 4.7 W = 0.048 (A) = 48 mA
6. Check that the current value is within the following range.
breakdown because of the potential difference generated by the charged
+5
electrostatic load, etc. on clothing and the human body. During repairY Current value of the label,-11 mA(25°C)
pay attention to electrostatic breakdown and also use the procedure inVariation by temperature : 0.4mA°C /
the printed matter which is included in the repair parts.Current increases with temperature increased.
The flexible board is easily damaged and should be handled with care.Current decreases with temperature decreased.
If the current is more than the range above, there is a trouble in the
NOTES ON LASER DIODE EMISSION CHECKautomatic power control circuit or the laser diode is in deterioration.
The laser beam on this model is concentrated so as to be focused on theIf less than the range, a trouble exists in the automatic power control
disc reflective surface by the objective lens in the optical pick-up block.circuit or the optical pick-up.
Therefore, when checking the laser diode emission, observe from more
than 30cm away from the objective lens.[MAIN BOARD] (Side B)
Before Replacing the Optical pick-up Block
Please be sure to check thoroughly the parameters as per the OOptical
pick-up Block Checking Procedure� (Part No. : 9-960-027-11) 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 disc motor.
Y S curve P-to-P value : 0.9 � 1.5Vp-p IC501 #� pin. (Connect pin !a
of IC501 (TP880) and 3 of IC501 (GND) with a jumper wire).
When checking S curve P-to-P value, remove the lead wire to disc
motor.
Y Adjusted part for focus gain adjustment : RV503
Y RF signal P-to-P value : 0.8 � 1.2Vp-p
Y Traverse signal P-to-P value : 1.0 � 2.4Vp-p
Y The repairing grating holder is impossible.
Y Adjusted part for tracking gain adjustment : RV502
Laser Diode Checking Methods
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).
The following two checking methods for the laser diode are operable.digital voltmeter
Method-1 (In the service mode or normal operation) :
Emission of the laser diode is visually checked.TP506
1. Open the upper lid.
2. Push the S801 as shown in Fig. 1-1 .
TP547
3. Check the object lens for confirming normal emission of the laser
diode. If not emitting, there is a trouble in the automatic power
TP102
control circuit or the optical pick-up. During normal operation, the D105
FB101
laser diode is turned ON about 2.5 seconds for focus searching.
C108C105
FB302
D804
R807TP306C205
Q101
C520
Q201
TP302
C208 TP202
D205
FB201
R521
S801L502TP522TP508
TP521TP515
TP507
Q501
C525R512
C514TP503TP514 R519 (TEO) C501
C516
R517TP509 TP502TP511
R501
TP534 TP512TP533
R510
Fig.1-1 Method to push S80132 3025C599C598R502R503R504 (VC)
TP547C517
TP506
R5051TP52324
C512IC501C503
Method-2 (In the service mode or normal operation) :5C51120C505 TP513(RFO)TP504
C510
C506
Check the value of current flowing in the laser diode.817C513TP540
8
1. Remove the upper panel.R549L5084C504C571
2. Read the current printed on the rear side of the optical pick-up.
(Print on the rear side of the optical pick-up)Fig. 1-2 Digital Voltmeter Connecting Location
3. Connect a level meter as shown in Fig. 1-2
4. Press the ^ key.
AC2211397
current valueyear
A : less than 48 mAmonth
date
shift No.
line No.
version
� 3 � |
ACEC
