Sony SLV-360 - Page 3

SAFETY CHECK-OUT
After correcting the original service problem, perform the following
safety checks before releasing the set the customer:
Check the area of your repair for unsoldered or LEAKAGE TEST
poorly-soldered connections. Check the entire board
surface for solder splashes and bridges. The AC leakage from any exposed metal part to earth
2. Check the interboard wiring to ensure that no wires ground and from all exposed metal parts to any exposed
are "pinched" or contact high-wattage resistors. metal part having a return to chassis, must not exceed 0.5
3. Look for unauthorized replacement parts, particularly mA (500 microampers). Leakage current can be measured
transistors, that were installed during a previous by any one of three methods. ,
repair. Point them out to the customer and
recommend their replacement. ; 1.
' 4. Look for parts which, though functioning, show
obvious signs of deterioration. Point them out to the
customer and recommend their replacement. 2.
5. Check the line cord for cracks and abrasion.
Recommend the replacement of any such line cord to
the customer. . 3,
6. Check the B+ voltage to see it is at the values
specified.
7. Check the antenna terminals, metal trim, "metallized"
knobs, screws, and all other exposed metal parts for
AC leakage. Check leakage as described below.
To Exposed metal
Parts on Set
AC
|_/| voltmeter
>} (0.75V)
== Earth Ground
Fig. A. Using an AC voltmeter to: check AC leakage.
Acommercial leakage tester, such as the Simpson 229
or RCA TW-540A. Follow the manufacturers’
instructions to use these instruments.
A battery-operated AC milliammeter. The Data
Precision 245 digital multimeter is suitable for this
job.
Measuring the voltage drop across a resistor by means
of a VOM or battery-operated AC voltmeter. The
"limit" indication is 0.75V, so analog meters must
have an accurate low voltage scale. The Simpson 250
and Sanwa SH-63Trd are examples of a passive VOM
that is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are suitable.
(See Fig. A)