SAFETY CHECK-OUT
CAUTION
Use of controls or adjustments or performance of procedures
After correcting the original service problem, perform the follow-
other than those specified herein may result in hazardous ra-
ing safety checks before releasing the set to the customer:
diation exposure.
Check the antenna terminals, metal trim, Ometallized� knobs, screws,
and all other exposed metal parts for AC leakage. Check leakage as
Notes on chip component replacement
described below.
Y Never reuse a disconnected chip component.
Y Notice that the minus side of a tantalum capacitor may be
LEAKAGE
damaged by heat.
The AC leakage from any exposed metal part to earth Ground and
from all exposed metal parts to any exposed metal part having a
Flexible Circuit Board Repairing
return to chassis, must not exceed 0.5 mA (500 microampers). Leak-
Y Keep the temperature of soldering iron around 270uC
age current can be measured by any one of three methods.
during repairing.
1. A commercial leakage tester, such as the Simpson 229 or RCA
Y Do not touch the soldering iron on the same conductor of the
WT-540A. Follow the manufacturersO instructions to use these
circuit board (within 3 times).
instruments.
Y Be careful not to apply force on the conductor when soldering
2. A battery-operated AC milliammeter. The Data Precision 245
or unsoldering.
digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a VOM
Laser component in this product is capable of emitting radiation
or battery-operated AC voltmeter. The Olimit� indication is 0.75
exceeding the limit for Class 1.
V, so analog meters must have an accurate low-voltage scale.
The Simpson 250 and Sanwa SH-63Trd are examples of a pas-
sive VOM that is suitable. Nearly all battery operated digitalThis appliance is classified as
multimeters that have a 2V AC range are suitable. (See Fig. A)a CLASS 1 LASER product.
The CLASS 1 LASER PROD-
UCT MARKING is located on
To Exposed Metalthe rear exterior.
Parts on Set
The following
caution label is
located inside of
AC
the unit.
0.15?Fvoltmeter
1.5kW
(0.75V)
Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.
NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK
OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic
break-down because of the potential difference generated by the
SAFETY-RELATED COMPONENT WARNING !!
charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also
COMPONENTS IDENTIFIED BY MARK ! OR DOTTED LINEuse the procedure in the printed matter which is included in the
WITH MARK ! ON THE SCHEMATIC DIAGRAMS AND INrepain parts.
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.The flexible board is easily damaged and should be handled with
REPLACE THESE COMPONENTS WITH SONY PARTScare.
WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS
NOTES ON LASER DIODE EMISSION CHECK
MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.
The laser beam on this model is concentrated so as to be focused on
ATTENTION AU COMPOSANT AYANT RAPPORT
the disc reflective surface by the objective lens in the optical pick-
� LA S?CURIT?!!
up block. Therefore, when checking the laser diode emission, ob-
LES COMPOSANTS IDENTIFI?S PAR UNE MARQUE ! SURserve from more than 30 cm away from the objective lens.
LES DIAGRAMMES SCH?MATIQUES ET LA LISTE DES
PIéCES SONT CRITIQUES POUR LA S?CURIT? DELASER DIODE AND FOCUS SEARCH OPERATION
FONCTIONNEMENT. NE REMPLACER CES COMPOSANTSCHECK
QUE PAR DES PIéCES SONY DONT LES NUM?ROS
Carry out the OS curve check� in OCD section adjustment� and check
SONT DONN?S DANS CE MANUEL OU DANS LES
that the S curve waveform is output three times.
SUPPL?MENTS PUBLI?S PAR SONY.
� 3 � |
ACEC
