akira CT-21CBS5CPH, Руководство по обслуживанию

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Model no.:CT-21CBS5CPH.doc
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3. High Voltage Inspection
Measure voltages of test points on the main PCB with the digital voltmeter. Measure the
CRT high voltage with the high-voltage testing equipment and heater voltage with the
high-frequency effective voltmeter. The rated values are shown as below.
Table 2
Test Point
Voltage (V)
Negative of VD461 26 / 1V
Negative of VD485 190 / 5V
CRT Anode 27 / 1.5KV
Heater 6.3 / 0.3Vrms
4. Focus Adjustment
Caution: Dangerously high voltages are present inside the TV. Extreme caution should be
exercised when working on the TV with the back removed.
4.1 After removing the back cover, look for the FBT on the main PCB. There should be a
FCB on the FBT.
4.2 Power on the TV and preheat it for 15 min.
4.3 Receive a normal TV signal. Rotate knob of the FCB until you get a sharp picture.
Fig. 4
5. Safety Inspection
5.1 Inspection for insulation and voltage-resistant
Perform safety test for all naked metal of the TV. Supply high voltage of 3000V AC,
50Hz (limit current of 10mA) between all naked metal and cold ground. Test every
point For 3 sec. and ensure no arcing and sparking.
5.2 Requirements for insulation resistance
Measure resistance between naked metal of the TV and feed end of the power cord to
be infinity with a DC-500 high resistance meter and insulation resistance between the
naked metal and degaussing coil to be over 200m
Ω