Why does the TV have a black screen and can t start when the TV is powered the power indicator is o

Fault analysis: First, the indicator light is on to indicate that the 220V power supply is normal, the fuse is not broken, the degaussing circuit is also normal, and usually the 300V circuit is not faulty.

Second, in view of the fact that the standby state is also the same, the standby state is handled first. First of all, use the remote control to turn on, and check whether the remote control battery is not.

Loose. or no battery (replace with another battery). Next, press the TV button to standby or change the channel button. Supplement the TV set with some bands individually.

If it is a TV state but the TV is on a channel with no signal, it is also the above phenomenon, and this possibility should be ruled out first.

Third, if it doesn't work, it means that the TV circuit is faulty. Usually it's a power supply or line scan. Of course, the power supply is the first to check the switch tube, and the line is the first to scan.

Line tube and counter-path capacitance. For non-professionals, it is recommended to ask a home appliance repairer to deal with it.

New TV,Generally, the line pipe or field block is broken,Generally, it can be replaced directly,Old TV may also have poor contact with the power potentiometer。

In general, this is a problem with the load circuit.

The power indicator is on.

Explain that there is no problem with the power supply.

The fault should be in the line scan circuit and the line power supply circuit.

If you are not a professional maintenance person, it is recommended that you do not repair it yourself.

It is prone to danger and can cause greater failures.

It is recommended that you find a skilled professional to carry out the repairs to avoid danger.

Answer: Hello,1、When the TV has a black screen, sometimes it turns on normally,When it is turned off and turned on again, there is a black screen or a color bar of a branch,It may be that there is a problem with the voltage of the power supply。 Originally, the output voltage was 5V, but now the output voltage is lower than 5V, then the voltage output is obviously abnormal. 2、After the TV is turned on, only the brand name appears on the black screen,This is a common problem of the backlight board,Generally, when this problem occurs, the high-voltage inverter and control transistor of the backlight board are empty welded。

3、When the TV is turned on and the screen is black, there is a situation with sound and characters, which means that the circuit is basically normal,The luminous conditions of the picture tube are available,Its failure is mainly the failure of the brightness channel or the loss of the brightness signal、Decoding circuit failure。

After the TV series is turned on, the indicator light shows that the switching power supply is working normally, there is a voltage output, and the screen is not lit for nothing more than two reasons, the screen is faulty and the power board is abnormal, it is recommended to check the power board circuit.

1. If the power supply is normal and the line part is not working, it may be that the collector voltage of the line pusher tube is abnormal, and if it is normal, focus on checking and repairing the output part of the line, and the line of the line output part can be completely closed.

2. If it is the reason for the protection circuit, it should be determined first what the protection action is. Disconnect each protection branch one by one, troubleshoot the fault, and then check it separately. After finding the problem, you can replace the resistance wire.

3. If the collector voltage of the row push tube is abnormal, first eliminate the fault of the push pole itself, and then repair the row oscillation circuit. It is generally common to open the supply resistor because of the line. Closing it will solve the problem.

4. If the power supply cannot work normally for overcurrent protection or current over-current, focus on checking the load circuit and output transformer. A protective socket strip can be replaced to solve the problem.

The TV screen is suddenly black, and the power light is not on, what is the reason?

Hello dear, I'm happy to answer for you, there are many reasons: 1. The power supply of the TV is faulty; 2. Disassemble the TV case to check the power fuse, and find that it has been fused, so you can judge that the power supply circuit or load circuit is seriously short-circuited; 3. The power supply regulator circuit of the driver board in the TV is faulty. Suggested treatment method 1: Unplug the TV power board F2 and the main circuit wrench plug-in CN2607, replace the fuse and power on the test machine, and the fuse will not be burned again; 2. Measure whether the B pole voltage of the line tube has a normal negative voltage, if there is no voltage, it means that before the family of the line is raised, the oscillation circuit and the line push circuit are not working normally, so focus on checking the line of oscillation circuit components; 3. Check the power switch of the TV, confirm that the socket is powered by the power supply, if not, the light is not lit, the power board is broken; 4. If there is a problem with the signal processing circuit of the post-stage, and some of the circuits are damaged, the load will be increased, and the 5V voltage will be pulled very low, and the components with problems in the post-stage will be checked one by one, and the faulty components will be replaced after the faulty components are replaced, and the 5V can be restored to normal, and the fault will be solved; 5. If the voltage of the image tube is abnormal, it is necessary to check whether the power supply of 200V is abnormal, and if the power supply voltage is abnormal, you need to purchase a voltage regulator.

In the case of virtual welding of the line, it is necessary to re-weld the virtual welding place of the line, and adjust the situation of the open circuit.

When the power indicator lights on and the TV does not work, there is a problem with the power output load, and the power output part detects that the output circuit is faulty, and the power supply protection will be activated. The case can be opened to see if there is any obvious component damage. For example, electrolytic capacitors bulge, fluid, resistors are blackened and burned, transistors and integrated circuits are bursting, and so on.

If there is no obvious device damage, it is necessary to disconnect part of the power supply output and part of it to check which working circuit is faulty.

The LCD TV screen is black, but the indicator light is normal, what is the problem?

The TV screen is suddenly black, and the power light is not on, what is the reason?

Hello, I'm glad to serve you, the TV suddenly goes black and the power light is not on, if the power circuit input level is faulty, check whether the 12V voltage is normal, whether the 5V voltage is there or whether it has become extremely low, that is, the fire or voltage regulator chip failure. If the backlight circuit of the Lubang drive is damaged, connect the display to the host to check the boot, it may be that the fuse of the high-voltage board is burned off and the switch chip is faulty, etc., and the relevant parts can be replaced. The above suggestions are only for reference, I hope it will help you!

<> the TV suddenly turns black and the power light does not turn on, if the Chang's belt is a nuclear finch level fault in the power supply circuit input, check whether the 12V voltage is normal, whether the 5V voltage is or whether it has become extremely low, that is, the fuse or voltage regulator chip is faulty. If the drive backlight circuit is damaged, connect the display to the host to check the reed-resistant reed, it may be that the fuse of the high-voltage board is burned off and the switch chip is faulty, etc., and the relevant parts can be replaced.