SECTION 1
SERVICING NOTE
SAFETY CHECK-OUT
NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK
(US model only)OR BASE UNIT
After correcting the original service problem, perform the follow-The laser diode in the optical pick-up block may suffer electrostatic
ing safety checks before releasing the set to the customer:
Check the antenna terminals, metal trim, Ometallized� knobs, screws,breakdown because of the potential difference generated by the
charged electrostatic load, etc. on clothing and the human body.
and all other exposed metal parts for AC leakage. Check leakage as
described below.During repair, pay attention to electrostatic breakdown and also use
the procedure in the printed matter which is included in the repair
LEAKAGEparts.
The flexible board is easily damaged and should be handled with
The AC leakage from any exposed metal part to earth Ground and
from all exposed metal parts to any exposed metal part having acare.
return to chassis, must not exceed 0.5 mA (500 microampers). Leak-
age current can be measured by any one of three methods.NOTES ON LASER DIODE EMISSION CHECK
1. A commercial leakage tester, such as the Simpson 229 or RCAThe laser beam on this model is concentrated so as to be focused on
WT-540A. Follow the manufacturersO instructions to use these
the disc reflective surface by the objective lens in the optical pick-up
instruments.block. Therefore, when checking the laser diode emission, observe
2. A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.from more than 30 cm away from the objective lens.
3. Measuring the voltage drop across a resistor by means of a VOM
or battery-operated AC voltmeter. The Olimit� indication is 0.75LASER DIODE AND FOCUS SEARCH OPERATION CHECK
V, so analog meters must have an accurate low-voltage scale.
The Simpson 250 and Sanwa SH-63Trd are examples of a pas-Carry out the OS curve check� in OCD section adjustment� and check
that the S curve waveform is output repeatedly.
sive VOM that is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are suitable. (See Fig. A)
COLD RESET
This mode erases all the data memorized on the user memory of this
To Exposed Metalunit and sets to the same state as shipment. Take note not to set it
Parts on Setaccidentally. To set cold reset, press the POWER button while press-
ing the CLEAR button.
The backup memory of this unit will be saved for about one month.
POSITIONING ON THE OSD (ON SCREEN DISPLAY)AC
SCREEN
0.15?F1.5kWvoltmeter
(0.75V)
This unit can display disc titles, etc. on the TV screen. The screen
position can be adjusted to correct screen deviations of the TV moni-
tors used. Turn on the power and press the OPEN button to open the
front cover. Then press the TIME/TEXT button next to display the
Earth Ground
position of the screen. The position can be adjusted by pressing the
Fig. A. Using an AC voltmeter to check AC leakagecursor button of the remote control unit supplied..
SAFETY-RELATED COMPONENT WARNING !!ATTENTION AU COMPOSANT AYANT RAPPORT
� LA S?CURIT?!!
COMPONENTS IDENTIFIED BY MARK ! OR DOTTED LINELES COMPOSANTS IDENTIFI?S PAR UNE MARQUE ! SUR
WITH MARK ! ON THE SCHEMATIC DIAGRAMS AND INLES DIAGRAMMES SCH?MATIQUES ET LA LISTE DES
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.PIéCES SONT CRITIQUES POUR LA S?CURIT? DE
REPLACE THESE COMPONENTS WITH SONY PARTSFONCTIONNEMENT. NE REMPLACER CES COMPOSANTS
WHOSE PART NUMBERS APPEAR AS SHOWN IN THISQUE PAR DES PIéCES SONY DONT LES NUM?ROS
MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.SONT DONN?S DANS CE MANUEL OU DANS LES
SUPPL?MENTS PUBLI?S PAR SONY.
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ACEC
