Advertisement
No modification of any circuit should be attempted. Service worker should only be performed after going
through to familiar with all of the following safety checks and servicing guidelines.
2-2. SAFETY CHECK
Care should be taken while servicing this
circuit. These voltages are exposed in such areas as the associated transformer circuits.
2-3. POWER SUPPLY REQUIREMENTS
The internal power converter with the attached AC power cord is necessary for the TV monitor. Any attempt to
replace another power converter could result in serious of problems on the display.
2-4. LEAKAGE CURRENT HOT CHECK
2-4-1 Plug the AC cord directly into the AC outlet. Do not use an isolation transformer during this check.
2-4-2 Connect a 1500 ohm, 10 watt resistor, paralleled by a 0.15uF capacitor between each metallic part and a
good earth ground.
2-4-3 Use an AC voltmeter with 1000 ohm / volt or more sensitivity and measure the AC voltage across
combination 1500 ohm resistor and 0.15uF capacitor.
2-4-4 Move the resistor connection to each exposed metallic part and measure the voltage.
2-4-5 Reverse the polarity of the AC plug in the AC outlet and repeat the above measurement.
2-4-6 Voltage measured must not exceed 1.5 volt RMS, from any exposed metallic part to the ground.
A leakage current tester may be used in the above hot check, in which case any circuit measured
must not exceed 1 milliamp. In the case of a measurement exceeding the 1 milliamp value, the rework is
required to eliminate the chance of a shock hazard.
CHAPTER 3:
TV display. Because of the high voltage is used in the inverter
AC VOLTMETER
V
0.15u
.
1500
To Metal Parts
10W
Earth Ground
PRODUCT ROUGH SPEC
the
5
Advertisement
