Troubleshooting and maintenance of lehua color tv.

Since the founding of New China, the living standards of most families have been getting better and better. At the same time, we have become more and more dependent on television. Television can not only kill our boring spare time, but also get us a lot of current affairs news. But when TV is used for a long time, there will always be big or small problems. What should we do when the TV is out of order? Lehua color TV is a very high-quality home TV. Next, I will introduce the common faults and maintenance methods of Lehua color TV.

Lehua LCD TV will be turned off from time to time, and its failure phenomenon is irregular. ? After disassembling the back cover of the TV set, three problems appeared in the trial operation for about half an hour. The measured power supply voltage is normal, and there is no 24V and on-off voltage. After measuring the voltage, it was found that 3.3v dropped to 2.7V and immediately returned to 3.3V. It was suspected that the thermal stability of the standby power block FSL206MR was poor.

Lehua color TV will automatically search for channels without saving them. There will be a pause when the automatic search has a station, but the station number will not change, so the station cannot be saved. The failure of TV storage is generally related to AFT signal. In the early CIKT color TV, the capacitance inside the AFT loop was mostly changed, but the small signal processing block used in this machine was TB 1238, and there was no AFT loop. In this case, first consider adjusting the bus data.

A Lehua color TV is turned on, the red indicator light of the power supply flashes, the speaker has intermittent noise, and the screen is black. ? After this fault occurs, it should be analyzed and repaired: the main voltage of the power supply is mainly monitored, and it is found that the voltage fluctuates between 6V and 80V with intermittent noise. Then solve this problem.

When watching TV programs in thunderstorm weather, a Lehua color TV set only heard the machine "bang", and then three faults appeared. Analysis may be that lightning rushed into the power grid, causing 220? V voltage fluctuation damages the switching power supply of this machine, so it is very important to detect the switching power supply and each power supply voltage of this machine. After turning on the TV, it is found that the AC delay fuse tube is black, indicating that there is a short circuit in the power supply. After testing, it was found that the power switch tube had been broken down, and no problems were found in other components. Replace the power switch tube and disconnect +B? 1 12? V rear load, connected to 100? W bulb is used as dummy load, and it is found that the bulb is slightly bright and flickering. The +B voltage measured by multimeter is 60 ~ 85? V, it is suspected that the voltage stabilizing circuit and the pulse width control circuit are faulty. Therefore, we should try to avoid turning on the TV in thunderstorm weather.

Have you gained any knowledge after reading the faults and maintenance of these Lehua color TVs? Television is a small partner in our life. We should watch it often, so as to ensure that all parts of TV work normally. If we don't watch it often, it's easy to break down because the inside of the TV needs to be kept dry. If you don't watch it for a long time, there will be various problems on TV. So we have to turn on the TV for a while every day. But we should also pay attention to protection when using it. So that they can accompany us for a long time.