Whether the indicator light is on or not: this problem is to measure whether the power supply voltage of CPU is normal first. Traditionally, the power supply is generally +5V. If it is normal, you can check whether the collector voltage of the line push transistor is normal. The new TV line push power supply is generally taken from the 25V field power supply voltage, which is realized by resistor voltage division, and some of them are taken by themselves, which is obtained after resistor voltage division, depending on whether the voltage division resistor fails or becomes larger.
If the voltage divider resistor fails, it will usually cause the collector voltage of the row push transistor to drop a lot or no voltage at all, resulting in no push signal of the row output tube, which will lead to the darkening of the screen. This situation is more common in summer.
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Precautions for users watching TV:
When turning on the TV, the user should plug in the power plug first and then turn on the power switch. You can't switch the TV by plugging and unplugging the power plug, because the current may be very large at the moment of plugging and unplugging the power plug, and such a large current directly output to the TV may cause chip breakdown. In addition, it is not advisable to switch the TV on and off frequently, and do not adjust various buttons at will.
The color, volume and contrast of large-screen color TV should be properly adjusted, so that the viewing effect can be better, the energy-saving effect can be achieved, and the service life of TV can be prolonged.
When using large-screen color TV, don't cover it with plastic sheets or cloth covers. And don't put foam on the bottom. In order not to affect the ventilation and heat dissipation of color TV, anti-static cloth covers should be used when necessary.