Half of the LCD TV is normal, half of it is black, and it is normal after an hour

Maybe the cable contact is poor, look for after-sales service.

Half of the TV screen is black and half black, which may be due to the abnormal sawtooth wave of the field oscillation circuit and the time constant of the counter-path blanking circuit is too large. The overhaul of the scanning circuit has a high technical content, and should be tested and repaired in part and in part according to on-site testing and judgment.

1. "The upper part of the screen is about 1 3 is a black screen, and the rest is good" means that the field scanning is still working, but it is in an abnormal scanning state. There are roughly two causes of failure, please judge carefully:

2. The sawtooth wave of the field oscillation circuit is abnormal (deformed), resulting in no image in 1 3 places on the screen. At this time, the image is characterized by the phenomenon of "curling" in the upper part; The time constant of the reverse path blanking circuit is too large, causing about 1 3 of the upper part of the image to be suppressed by the blanking circuit, resulting in a black screen of about 1 3 of the upper part of the image, and there is no distortion of the image at this time.

Principles of television

Television uses electricity to transmit visual images of the event in real time. Similar to movies, TV uses the visual residual effect of the human eye to show a still image with a gradual change of frames, forming a visual living image. The transmitter of the TV system converts the various fine parts of the scene into electrical signals according to brightness and chromaticity, and transmits them sequentially.

At the receiving end, the luminance and chromaticity of each fine part are displayed according to the corresponding geometric position to reproduce the entire original image. The scanning system of television signals in various countries is not exactly the same as that of channel broadband, and is distinguished by Latin letters according to the recommendations of the International Radio Advisory Committee (CCIR).

The reasons for this situation in LCD TVs are: First, the LCD backlight of LCD TVs is broken.

The second is caused by the failure of the LCD screen of the LCD TV.

The third is caused by poor line contact or power supply problems.

First of all, check whether the screen line on the logic board is in poor contact and so on.

If the above checks are normal, then measure whether the supply voltage of the logic board circuit is normal

12v)。If the above measurement is normal, then measure whether the voltage of each output pin to ground is normal for all DC-DC voltage conversion circuit chips on the logic board.

Item. If the components around the measurement chip are abnormal, then the fault may be due to the internal circuit of the logic board being abnormal or damaged.

Wait. Note: It is best to use measurement methods for the above suggestions, and after finding the fault point, consider the plate problem.

Faulty backlight. You may need after-sales or repairman to deal with it.

Summary. Hello! 1. There may be a problem with the power connection of the TV. 2. It may be that you pressed the standby button of the remote control by mistake, which makes the TV enter the standby state. 3. It may be caused by hardware failure. 4. It may be that a time limit is set**.

Suggested Treatment:

1. If the power indicator of the TV is not lit, it may be that the power connection of the TV is abnormal, resulting in a sudden power failure and a black screen, such as whether there is a power outage at home, whether the power plug is loose, whether the power cord is faulty, etc., you can check one by one and find out the problem and deal with it accordingly.

2. If the power indicator of the TV is on, it may be that the user accidentally pressed the standby button of the remote control, which makes the TV start to enter the standby state, so the black screen is displayed, at this time, you only need to press the standby button of the remote control again, you can wake up the TV and restore it to the normal screen display state.

3. If the TV screen is still black after the above methods are checked, it may be caused by hardware failure, such as a failure of the power module, a short circuit or an open circuit at the switching circuit, a failure of the high-voltage board, a failure of the LCD screen or screen cable, a motherboard chip or other parts.

What is going on with the TV set that is half black and half normal.

Hello! 1. There may be a problem with the power connection of the TV. 2. It may be that you pressed the standby button of the remote control by mistake, which makes the TV enter the standby state.

3. It may be caused by hardware failure. 4. It may be that a time limit is set**Suggested handling method: 1. If the power indicator of the TV is not lit, it may be that the power connection of the TV is abnormal, resulting in a sudden power failure and a black screen, such as whether there is a power outage at home, whether the power plug is loose, whether the power cord is faulty, etc., you can check them one by one and find out the problem and deal with it accordingly.

2. If the power indicator of the TV is on, it may be that the user accidentally pressed the standby button of the remote control, which makes the TV start to enter the standby state, so the black screen is displayed, at this time, you only need to press the standby button of the remote control again, you can wake up the TV and restore it to the normal screen display state. 3. If the TV screen is still black after the above methods are checked, it may be caused by hardware failure, such as a failure of the power module, a short circuit or an open circuit at the switching circuit, a failure of the high-voltage board, a failure of the LCD screen or screen cable, a motherboard chip or other parts.

4. First of all, see if the time limit is set**, if it is left with a black screen, turn it off and open it after a while and it is normal, so repeatedly, you can enter the menu to cancel the time limit**, that is, the time item is zero, so you can.

How to solve the problem that the TV is half bright and half dark.

Hello! Need to change the screen,**Half of the original price of the original TV。

When the TV screen is half black.

In half of the good cases, four factors should be considered: first, the backlight plate of the TV screen is abnormal; second, there is an interference source next to the TV; the third is that the TV has a long service life; Fourth, the sawtooth wave of the field oscillation circuit is abnormal, and the time constant of the counter-path blanking circuit is exemplary.

On the large side. The specific reasons and solutions for the TV screen to appear half black and half good: 1. The backlight plate of the TV screen is abnormal.

Generally, there is a problem with the lamp of the backlight panel, and it can be replaced. 2. If there is an interference source next to the TV, it is recommended that the user remove the electrical appliances and equipment with magnetic field interference on the side of the TV. The TV circuit is soldered.

The user needs to find out the position of the virtual soldering of the circuit, and after finding the position of the virtual soldering of the TV, the virtual soldering place is re-welded, and the phenomenon of flickering and dimming of the image can be solved by connecting it. 3. The TV has a long service life, and the aging and deterioration of electronic components or too much dust in the machine will cause the machine to overheat and cause the components to burn, so it is recommended that users replace the new TV and prevent the aging TV from radiating. 4. It may be that the sawtooth wave of the field oscillation circuit is abnormal, and the time constant of the counter-path blanking circuit is too large.

The field oscillation circuit has an abnormal sawtooth wave (distortion), resulting in no image at the top 1 2 of the screen. At this time, the image is characterized by the phenomenon of "curling" in the upper part; b. The time constant of the reverse path blanking circuit is too large, resulting in about 1 2 of the upper part of the image being suppressed by the blanking circuit, resulting in about 1 2 black screen of the upper part of the image, and there is no deformation of the image at this time. The overhaul of the scanning circuit has a high technical content, and should be tested and repaired according to the on-site inspection and judgment.

If your TV has a half-black screen and half a normal hunger disorder, here are some possible solutions:

1.Restart the TV: Try turning off the TV and restarting it. This can often fix many common problems, such as black screen glitches.

2.Check the power cord: Make sure your TV's power cord is securely connected. If the power connection is loose or damaged, the TV may not function properly.

3.Check the source: Make sure your TV is receiving the correct source. If your TV doesn't support the channel you're using, you may need to change sources.

4.Reset your TV: If your TV supports reset, try using the reset feature to fix the problem. Many TV models have a reset button that you can do by following the instructions on your TV.

5.Clean the screen and shout back: If the TV screen is contaminated or worn, it can cause a black screen failure. Try using a high-consumption cleaner and a soft cloth to gently clean the screen.

6.Update your TV software: If your TV supports software updates, try updating your TV software. Many TV models require regular software updates to function properly.

If you are unable to resolve the issue, it is recommended that you contact 400-698-7786 or a professional repairer. They may provide you with more professional advice and solutions.

LCD TV half black screen.

Half of the normal what's going on: 1. Check the logic board first for this failure.

Whether the upper screen line is not in good contact and so on.

2. If the above checks are normal, then measure whether the power supply voltage of the logic board circuit is normal.

3. If the above measurement is normal, then measure it, all DC-DC voltage conversion circuit chips on the logic board, and the voltage of each output pin to the ground is normal, if there is any abnormality, check the components around the abnormal pins of the chip.

4. If the components around the front foot of the measurement chip are abnormal, then the fault problem may be due to the abnormal or damaged circuit of the trace cleaning part of the logic board.

This answer is applicable to Hisense75E3D、SKYWORTH98G91Brand TV models。

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Let you wait for a long time,The reasons and solutions are as follows:The failure of only half of the black screen is not common,If the mold type is now such a situation, it is recommended to use the following methods to deal with it:1、Replace the logic board of the TV; 2. Check that the cable of the ** is loose, and then replace it; 3. Re-repair the position of virtual welding in the TV.

The main reasons for this situation on TVs are mainly the following:1、Screen cable problem,This is the most likely to affect the imaging results of the TV,If the contact contact of the cable is poor or damaged, this situation will occur。 2. If the internal parts of the LCD TV are soldered, it will make Dan guess that the contact between the various parts is poor, and the digital signal will not be completely input into the system or even all lost during transmission, resulting in a black screen on half of the TV screen.

3. The common fault of the logic board is AS15-G, if the temperature is very hot to the touch, and the test voltage with a multimeter is also very abnormal, then we can basically determine that the logic board is suspicious of Kai and the fault is present. Focus: The maintenance of the scanning circuit has a high technical content, and should be detected and repaired in part and in part according to the on-site detection and judgment.

The repair is difficult, and it is recommended to find the TV brand manufacturer for repair.