Daewoo TVZ 1321, Service Manual

Page: 3 / 151

2
• 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 positions. Afterwards, perform the following tests and confirm the specified values in order to ver-
ify compliance with safety standards.
1. Insulation resistance test
Confirm the specified insulation resistance or greater between power cord plug prongs and externally exposed parts of
the set (RF terminals, antenna terminals, video and audio input and output terminals, microphone jacks, earphone jacks,
etc.). See table below.
2. Dielectric strength test.
Confirm specified dielectric or strength or greater between power cord plug prongs and exposed accessible parts of the
set(RF terminals, antenna terminals, video and audio input and output terminals, microphone jacks, earphone jacks,
etc.) See table below.
3. Clearance distance
When replacing primary circuit components, confirm spec-
ified clearance distance (d), (d") between soldered termi-
nals, and between terminals and surrounding metallic
parts. see table below.
Table 1 : Rating for selected areas
Note : This table is unofficial and for reference only. Be sure to confirm the precise values for your particular country and
locality.
4. Leakage current test
Confirm specified or lower leakage current between B (earth ground, power cord plug prongs) and externally exposed
accessible parts (RF terminals, antenna terminals, video and audio input and output terminals, microphone jacks, ear-
phone jacks, etc.)
Measuring Method : (Power ON)
Insert load Z between B (earth ground, power cord plug
prongs) and exposed accessible parts. Use an AC volt-
meter to measure across both terminals of load Z.
See figure 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 for your particular country and
locality.
AC Line Voltage Region
Insulation Dielectric Clearance
Resistance Strength Distance (d), (d')
100V Japan
≥
1M
Ω
500 V DC 1kV 1 minute
≥
3 mm
110 to 130V USA & Canada --- 900V 1 minute
≥
3.2mm
≥
6mm(d)
* 100 to 250V South America
≥
10 M
Ω
/500 V DC 4 kV 1 minute
≥
8mm(d')
(z:Power cord)
AC Line Voltage Region Load Z Leakage Current (i)
Earth Ground
(B) to :
100V Japan i
≤
1mA rms Exposed accessible parts
110 to 130 V USA & Canada i
≤
0.5 mA rms Exposed accessible parts
100 to 130 V South America
i
≤
0.7 mA peak
Antenna earth terminals
i
≤
2mA dc
200 to 250 V
i
≤
0.7 mA peak
Other terminals
i
≤
2mA dc
Fig. 1
Fig. 2
1k
Ω
2k
Ω
50k
Ω
1.5k
µ
F
1.5k
Ω