WATSON VR-3780, Service Manual

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2
SAFETY & PRECAUTIONS
SAFETY CHECK AFTER SERVING
Examine the area surrounding the repaired location for damage or deterioration. Observe that screw, parts and wires
have been returned to original positions. Afterwards, perform the following tests and conform the specified values in order
to verify compliance whit safety standards.
1. Insulation resistance test
Confirm the specified insulation resistance between power cord plug prong and externally exposed parts of the set
(RF terminals, antenna terminals, video and audio input and output terminals, microphone jacks, earphone jacks, etc.)
isgreater than values given in table 1 below.
2. Dielectric strengthen test
Confirm specified dielectric strengthen between power cord
plug prongs and exposed accessible parts of the set
(RF terminals, antenna terminals, video and audio input output
terminals, microphone jack, ear phone jacks, etc.)
is greater than values given table 1.
3. Clearance distance
When replacing primary circuit component, confirm specified clearance distance (d), (d
’
) between soldered terminals,
and between terminals and surrounding metallic parts. See table below.
Rating for selected areas
* : Class model only
AC Line Voltage Region
Insulation
Resistance
Dielectric
Strength
Clearance
Distance(d),(d)
100V Japan
>1M
Ω
/500V DC
1kV AC 1min.
> 3
110 to 130V
USA & Canada
- 900V AC 1min.
> 3.2
* 110 to 130V
200 to 240V
Europe
Australia
Latin America
>10M
Ω
/500V DC 4kV AC 1min.
> 6(d)
> 8(d')
(a :Power cord)
This table is unofficial and for reference only. Be sure to confirm the precise values for your
particular country and locality
NOTE