Symphonic ST27S3, Service Manual

Page: 7 / 52

2-4 L6115IMP
Safety Check after Servicing
Examine the area surrounding the repaired location
for damage or deterioration. Observe that screws,
parts and wires have been returned to original posi-
tions. Afterwards, perform the following tests and con-
firm the specified values in order to verify compliance
with safety standards.
1. Clearance Distance
When replacing primary circuit components, confirm
specified clearance distance (d) and (d') between sol-
dered terminals, and between terminals and surround-
ing metallic parts. (See Fig. 1)
Table 1 : Ratings for selected area
Note: This table is unofficial and for reference only. Be
sure to confirm the precise values.
2. Leakage Current Test
Confirm the specified (or lower) leakage current be-
tween B (earth ground, power cord plug prongs) and
externally exposed accessible parts (RF terminals, an-
tenna terminals, video and audio input and output ter-
minals, microphone jacks, earphone jacks, etc.) is
lower than or equal to the specified value in the table
below.
Measuring Method : (Power ON)
Insert load Z between B (earth ground, power cord
plug prongs) and exposed accessible parts. Use an
AC voltmeter to measure across both terminals of
load Z. See Fig. 2 and following table.
Table 2 : Leakage current ratings for selected areas
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
AC Line Voltage Region
Clearance
Distance (d) (d')
110 to 130 V
USA or
CANADA
≥
3.2 mm
(0.126 inches)
Chassis or Secondary Conductor
d d'
Primary Circuit Terminals
Fig. 1
AC Voltmeter
(High Impedance)
Exposed Accessible Part
B
Earth Ground
Power Cord Plug Prongs
Z
1.5k
Ω
0.15
µ
F
Fig. 2
AC Line Voltage Region Load Z Leakage Current (i) Earth Ground (B) to:
110 to 130 V USA
0.15µF CAP. & 1.5k
Ω
RES. connected in
parallel
i
≤
0.5mA rms
Exposed accessible
parts