Sofa butler after-sales maintenance TV time is long, there will always be a variety of faults, which is more common is the boot black screen, then this is what caused the cause? Today, Xiao Bian will take a look at the causes and solutions of Hisense TV's black screen.
First, the overall description of Hisense TV no image failure performance varied, there are two common types of failure, one is no image, the screen is not lit, there is a sound; the second is no image, the screen is bright, with sound. In addition, all sources have no image; AV/S/HDTV input has no image; HDMI input has no image; USB input has no image; VGA input has no image; there is only one horizontal bright line on the screen; there is only one vertical bright line on the screen; There is a retrace bright line; there is only red/green/blue color on the screen; there is no image on the screen; MITV has no image and so on.
Second, the black screen causes and solutions
1, the power circuit is not normal, showing no response when pressing the panel button, the indicator light does not shine. First check the normal 12V voltage, follow the check 5V voltage, because the A/D driver board signal processing part of the chip's operating voltage is 5V, so find the machine can not open the fault, first use a multimeter to measure 5V voltage, if there is no 5V The voltage or 5V voltage becomes very low, then one kind may be a problem in the input stage of the power circuit, that is to say, the power supply part of the 12V to 5V goes wrong.
This kind of fault is very common, usually burn insurance or voltage regulator chip failure, some of the machine is the built-in switching power supply, output two sets of power, one set is 5V for signal processing, the other set is 12V to provide high voltage For backlighting on the board, if there is a fault in the circuit of the switching power supply, it may result in no output of both sets of power supplies.
Another possibility is that the 5V load is getting heavier. The 5V voltage is pulled very low. In other words, the signal processing circuit at the rear stage has a problem, some of the circuits are damaged, and the load is aggravated, pulling the 5V voltage. Very low, one by one after the investigation of the problem of the components after the problem, replace the failed components, 5V can return to normal, the fault is generally resolved, but also often encountered after the 5V voltage returned to normal after the normal boot.
This situation also has a variety of reasons. On the one hand, the MCU program may be washed out, which may lead to no boot. There is also damage to the MCU itself. For example, the I/O port of the MCU is damaged and the MCU cannot scan the keys. Failure caused by the MCU, in the case of no way to find the original AD driver board replacement, can only find another way to find the A/D driver board that can be replaced
2. The power supply is normal. There may be a problem with the circuit that drives the backlight. The detection method is to connect the monitor to the host boot check, close to the screen carefully observed, if you see the display is very dark images, it proves that the A / D driver board signal processing part of the circuit is normal, the problem is locked in the drive Backlight high voltage board and control high voltage board switch function circuit, the common fault of the high voltage board has the high voltage board's own insurance burn out causing no 12V supply and switch chip failure and so on.
3, AD board control high voltage board switch part of the circuit is faulty, can not be output high to control the switch pin of the high voltage board, with a multimeter negative test lead grounding, is the test pen received control output pin, press the switch button, normal words It can be seen that there is a level change, but also can use a relatively simple method to determine whether the high voltage board is not good, that is to find the control of the high voltage board switch directly to the 5V voltage, high voltage board is not faulty Can light the backlight.
Another situation will cause a black screen, that is, the backlight of the screen is broken, but if it is a dual-lamp and four-lamp screen backlight at the same time bad is not possible, broken one of the lamps will cause a black screen, but with the black screen failure in front of The performance is different. This is because some high-voltage boards have unbalanced load protection. If a lamp is broken, the high-voltage board will enter the unbalanced load protection state after power on, and it will appear as a black screen after flickering.
4. Hisense checks the original circuit of U2 peripheral related circuit for failure. After replacing U2, it restarts to troubleshoot the fault. The black screen of the TV sometimes turns on normally, and when the black screen or the color bars of the branches appear when the camera is turned off and on again, there may be a problem with the voltage of the power supply. The voltage that should originally be output is 5V but the output voltage is now lower than 5V, then the voltage output is obviously not normal.
5. When Hisense TV turns on the black screen, there are sounds and characters. This shows that the circuit is basically normal. The light emitting conditions of the picture tube are all available. Its failure is mainly due to the failure of the luminance channel or the loss of the luminance signal and the decoding circuit. malfunction. When the brightness channel of the TV has a problem or the signal of the brightness is lost, such a problem is not our own solution. If this problem is not properly dealt with, it will cause the brightness channel to have no light required to transmit the screen at all. At that time, we must ask the special personnel to come to the door for maintenance. Defective decoding circuit can only replace the decoding circuit.
6. The reason for the black screen of the TV may be caused by the abnormality of the power circuit of the TV. The phenomenon of this problem shows no response to the panel keys and the indicator light is not on. The first problem with such a problem is to check if the TV 12V and 5V are normal. If the voltage is normal, there may be a problem with the number of stages of the input power circuit. This is generally because the power supply is burned or the voltage regulator chip has a problem. The TV's insurance is burned and the TV's insurance needs to be replaced.
7. The TV's power supply is normal. It may be a problem with the TV's driving backlight circuit that causes the TV's black screen to have a sound. At this time, the monitor needs to be connected to the host computer for boot check. When you get close to the screen, you can find the screen shows a very dark image, this can prove that the signal processing part of the driver board is normal, then the TV appears The reason for the problem is that the functional circuit of the high voltage control panel switch that drives the backlight malfunctions, so long as the troubleshooting of the functional circuit can restore the screen of the television.
8, other special circumstances.
Third, maintenance fees
Fifth, screen maintenance charges
Note:
One area is the following branch companies:
Qingdao, Jinan, Fuzhou, Xiamen, Hangzhou, Ningbo, Nanjing, Wuxi, Beijing, Tianjin, Dalian, Wuhan, Hefei
The second category is the following branch companies:
Shenyang, Harbin, Haikou, Hohhot, Changsha, Nanchang, Shijiazhuang, Taiyuan, Zhengzhou, Changchun, Xian, Nantong
The three types of regions are the following branches:
Nanning, Leshan, Luzhou, Nanchong, Panzhihua, Zunyi, Guiyang, Chengdu, Chongqing, Lanzhou, Mudanjiang, Jinzhou, Tonghua, Fuyang, Luohe, Zhangzhou, Linyi, Xuzhou, Tangshan
Other areas:
Branches of Guangdong, Kunming, Shanghai, Shenzhen, Wenzhou, and Xinjiang have implemented local inspection and installation fees because local household appliances industry associations have clear fees.
First, the overall description of Hisense TV no image failure performance varied, there are two common types of failure, one is no image, the screen is not lit, there is a sound; the second is no image, the screen is bright, with sound. In addition, all sources have no image; AV/S/HDTV input has no image; HDMI input has no image; USB input has no image; VGA input has no image; there is only one horizontal bright line on the screen; there is only one vertical bright line on the screen; There is a retrace bright line; there is only red/green/blue color on the screen; there is no image on the screen; MITV has no image and so on.
Second, the black screen causes and solutions
1, the power circuit is not normal, showing no response when pressing the panel button, the indicator light does not shine. First check the normal 12V voltage, follow the check 5V voltage, because the A/D driver board signal processing part of the chip's operating voltage is 5V, so find the machine can not open the fault, first use a multimeter to measure 5V voltage, if there is no 5V The voltage or 5V voltage becomes very low, then one kind may be a problem in the input stage of the power circuit, that is to say, the power supply part of the 12V to 5V goes wrong.
This kind of fault is very common, usually burn insurance or voltage regulator chip failure, some of the machine is the built-in switching power supply, output two sets of power, one set is 5V for signal processing, the other set is 12V to provide high voltage For backlighting on the board, if there is a fault in the circuit of the switching power supply, it may result in no output of both sets of power supplies.
Another possibility is that the 5V load is getting heavier. The 5V voltage is pulled very low. In other words, the signal processing circuit at the rear stage has a problem, some of the circuits are damaged, and the load is aggravated, pulling the 5V voltage. Very low, one by one after the investigation of the problem of the components after the problem, replace the failed components, 5V can return to normal, the fault is generally resolved, but also often encountered after the 5V voltage returned to normal after the normal boot.
This situation also has a variety of reasons. On the one hand, the MCU program may be washed out, which may lead to no boot. There is also damage to the MCU itself. For example, the I/O port of the MCU is damaged and the MCU cannot scan the keys. Failure caused by the MCU, in the case of no way to find the original AD driver board replacement, can only find another way to find the A/D driver board that can be replaced
2. The power supply is normal. There may be a problem with the circuit that drives the backlight. The detection method is to connect the monitor to the host boot check, close to the screen carefully observed, if you see the display is very dark images, it proves that the A / D driver board signal processing part of the circuit is normal, the problem is locked in the drive Backlight high voltage board and control high voltage board switch function circuit, the common fault of the high voltage board has the high voltage board's own insurance burn out causing no 12V supply and switch chip failure and so on.
3, AD board control high voltage board switch part of the circuit is faulty, can not be output high to control the switch pin of the high voltage board, with a multimeter negative test lead grounding, is the test pen received control output pin, press the switch button, normal words It can be seen that there is a level change, but also can use a relatively simple method to determine whether the high voltage board is not good, that is to find the control of the high voltage board switch directly to the 5V voltage, high voltage board is not faulty Can light the backlight.
Another situation will cause a black screen, that is, the backlight of the screen is broken, but if it is a dual-lamp and four-lamp screen backlight at the same time bad is not possible, broken one of the lamps will cause a black screen, but with the black screen failure in front of The performance is different. This is because some high-voltage boards have unbalanced load protection. If a lamp is broken, the high-voltage board will enter the unbalanced load protection state after power on, and it will appear as a black screen after flickering.
4. Hisense checks the original circuit of U2 peripheral related circuit for failure. After replacing U2, it restarts to troubleshoot the fault. The black screen of the TV sometimes turns on normally, and when the black screen or the color bars of the branches appear when the camera is turned off and on again, there may be a problem with the voltage of the power supply. The voltage that should originally be output is 5V but the output voltage is now lower than 5V, then the voltage output is obviously not normal.
5. When Hisense TV turns on the black screen, there are sounds and characters. This shows that the circuit is basically normal. The light emitting conditions of the picture tube are all available. Its failure is mainly due to the failure of the luminance channel or the loss of the luminance signal and the decoding circuit. malfunction. When the brightness channel of the TV has a problem or the signal of the brightness is lost, such a problem is not our own solution. If this problem is not properly dealt with, it will cause the brightness channel to have no light required to transmit the screen at all. At that time, we must ask the special personnel to come to the door for maintenance. Defective decoding circuit can only replace the decoding circuit.
6. The reason for the black screen of the TV may be caused by the abnormality of the power circuit of the TV. The phenomenon of this problem shows no response to the panel keys and the indicator light is not on. The first problem with such a problem is to check if the TV 12V and 5V are normal. If the voltage is normal, there may be a problem with the number of stages of the input power circuit. This is generally because the power supply is burned or the voltage regulator chip has a problem. The TV's insurance is burned and the TV's insurance needs to be replaced.
7. The TV's power supply is normal. It may be a problem with the TV's driving backlight circuit that causes the TV's black screen to have a sound. At this time, the monitor needs to be connected to the host computer for boot check. When you get close to the screen, you can find the screen shows a very dark image, this can prove that the signal processing part of the driver board is normal, then the TV appears The reason for the problem is that the functional circuit of the high voltage control panel switch that drives the backlight malfunctions, so long as the troubleshooting of the functional circuit can restore the screen of the television.
8, other special circumstances.
Third, maintenance fees
Fifth, screen maintenance charges
Note:
One area is the following branch companies:
Qingdao, Jinan, Fuzhou, Xiamen, Hangzhou, Ningbo, Nanjing, Wuxi, Beijing, Tianjin, Dalian, Wuhan, Hefei
The second category is the following branch companies:
Shenyang, Harbin, Haikou, Hohhot, Changsha, Nanchang, Shijiazhuang, Taiyuan, Zhengzhou, Changchun, Xian, Nantong
The three types of regions are the following branches:
Nanning, Leshan, Luzhou, Nanchong, Panzhihua, Zunyi, Guiyang, Chengdu, Chongqing, Lanzhou, Mudanjiang, Jinzhou, Tonghua, Fuyang, Luohe, Zhangzhou, Linyi, Xuzhou, Tangshan
Other areas:
Branches of Guangdong, Kunming, Shanghai, Shenzhen, Wenzhou, and Xinjiang have implemented local inspection and installation fees because local household appliances industry associations have clear fees.
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