CX-JS5
Notes on chip component replacementSAFETY CHECK-OUT
YNever reuse a disconnected chip component.After correcting the original service problem, perform the follow-
Y Notice that the minus side of a tantalum capacitor may be dam-ing safety check before releasing the set to the customer:
aged by heat.Check the antenna terminals, metal trim, Ometallized� knobs,
screws, and all other exposed metal parts for AC leakage.
Flexible Circuit Board RepairingCheck leakage as described below.
YKeep the temperature of the soldering iron around 270 uC dur-
ing repairing.LEAKAGE TEST
Y Do not touch the soldering iron on the same conductor of theThe AC leakage from any exposed metal part to earth ground and
circuit board (within 3 times).from all exposed metal parts to any exposed metal part having a
Y Be careful not to apply force on the conductor when solderingreturn to chassis, must not exceed 0.5 mA (500 microamperes.).
or unsoldering.Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturersO instructions to use these
CAUTION
Use of controls or adjustments or performance of proceduresinstruments.
2. A battery-operated AC milliammeter. The Data Precision 245
other than those specified herein may result in hazardous ra-digital multimeter is suitable for this job.
diation exposure.
3. Measuring the voltage drop across a resistor by means of a
VOM or battery-operated AC voltmeter. The Olimit� indica-
tion is 0.75 V, so analog meters must have an accurate low-
The following caution label is located inside the unit.voltage scale. The Simpson 250 and Sanwa SH-63Trd are ex-
amples of a passive VOM that is suitable. Nearly all battery
operated digital multimeters that have a 2 V AC range are suit-
able. (See Fig. A)
To Exposed Metal
Parts on Set
AC
0.15 ?F1.5 k&voltmeter
(0.75 V)
UNLEADED SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
Earth Groundthe lead free mark due to their particular size)
Fig. A. Using an AC voltmeter to check AC leakage.
: LEAD FREE MARK
Unleaded solder has the following characteristics.
Y Unleaded solder melts at a temperature about 40 uC higher than
ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350 uC.
SAFETY-RELATED COMPONENT WARNING!!Caution: The printed pattern (copper foil) may peel away if the
heated tip is applied for too long, so be careful!COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED
Y Strong viscosityLINE WITH MARK 0 ON THE SCHEMATIC DIAGRAMS
Unleaded solder is more viscou-s (sticky, less prone to floAND IN THE Pw)ARTS LIST ARE CRITICAL TO SAFE
than ordinary solder so use caution not to let solder bridges oc-OPERATION. REPLACE THESE COMPONENTS WITH
cur such as on IC pins, etc.SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUB-
LISHED BY SONY.Y Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.
ATTENTION AU COMPOSANT AYANT RAPPORT
� LA S?CURIT?!
LES COMPOSANTS IDENTIFI?S PAR UNE MARQUE 0
SUR LES DIAGRAMMES SCH?MATIQUES ET LA LISTE
DES PIéCES SONT CRITIQUES POUR LA S?CURIT?
DE FONCTIONNEMENT. NE REMPLACER CES COM-
POSANTS QUE PAR DES PIéCES SONY DONT LES
NUM?ROS SONT DONN?S DANS CE MANUEL OU
DANS LES SUPPL?MENTS PUBLI?S PAR SONY.
2 |
ACEC
