1, no image
Analysis and repair: class failure is mostly due to the logic board no supply voltage. Due to the different manufacturing process of the screen, - generally 26 inches and more than the screen in the logic board without supply voltage will screen, because at this time the backlight is bright, sometimes it will be shown as a gray screen; 26 inches below the screen is usually shown as a white screen. Repair should first check the logic board supply voltage is normal. If the voltage is normal, indicating that the signal board power supply circuit is working properly, then check the logic board on the insurance is blown. If the insurance is blown, in the case of confirming that there is no short circuit in the back stage, you can replace the insurance resistor a try. If there is no voltage or low voltage, then you can unplug the logic board on the screen line plug, and then test the signal board to send out the power is normal, levy normal, it shows that there is a short-circuit fault on the logic board, or else the problem is on the signal board.
2, there is an image, but the image color or contrast is abnormal
Analysis and repair: Measure the logic board at the data signal is normal, such as conditions can be measured on the waveform. In the actual measured waveform is not very clear, in order to determine, can be unplugged from the closed line, that is, in the absence of signal input, and again measured its waveform, so that by contrast to determine the presence of data signals. If there is no oscilloscope, you can use the method of measuring DC voltage to roughly determine. After a few minutes of power on the logic board with a hand touch the surface temperature of the integrated block, the normal should be slightly hot, if the temperature rises too quickly, - generally indicates that the circuit has a fault.
Typically, the logic board damage caused by the following failure phenomena: the image is not hierarchical, lack of detail or negative image; or active image trailing, clear
poor clarity; or the image is relief mounted, hard lines; or image of the local area on the color patch, color block.
3, vertical bars on the screen
Analysis and repair: this failure is divided into two categories: - is the full screen are colored vertical bars; the second is the image of the upper region of the vertical bars. Due to this type of failure and LCD damage failure phenomenon is very similar, - generally used to replace the same type of logic board to accurately determine the fault. If you replace the logic board, the fault remains, it shows that the LCD screen has a problem; otherwise, the original logic board failure.
Quickly determine the LCD TV logic board circuit faulty method:
1, test the logic board, sent by the digital image processing circuit input video signal waveform is normal, if there is a normal waveform input, indicating that the front of the digital image processing circuit work properly.
2, test the logic board by the power supply input voltage is normal, if the input voltage is normal, that the power supply circuit is working properly.
3, test the logic board on the screen interface output LCD drive signal waveform is normal, if there is no normal LCD drive signal waveform output, it is possible that the logic board circuit failure.
TV logic board damage repair costs:
The cost of repairing the TV is composed of two parts of the maintenance fee and parts fee, due to the LCD screen used by the TV is different, using the logic board is not the same, the corresponding price is not the same. Also depends on how many inches of LCD TV, according to the National Association of Home Appliance Repair charges such as 42-inch component level repair third level repair fee 240 + 30 _ door-to-door fee + parts fee.
Price from the network, for reference only.
Service outlets: Beijing, Tianjin, Guangzhou, Shanghai, Chongqing, Hefei, Anqing, Shenzhen, Zhuhai, Guilin, Harbin, Hangzhou, Shijiazhuang, Luoyang, Yueyang, Jinan, Changzhou, Kunshan, Nantong, Wuxi, Yangzhou, Nanchang, Shenyang, Nanjing, Fuzhou, Chengdu, Changsha, Zhengzhou, Suzhou, Nanning, Xi'an, Baoji, Taiyuan, Mianyang, Wuhan, Kunming, Ningbo, and other cities.
TV logic board damage solution keywords: logic board bad phenomenon picture, LCD TV driver board bad symptoms, how to determine the logic board bad or screen bad, TV logic board bad symptoms, LCD TV logic board schematic, LCD screen side board short circuit how to check, TV 40e3000 logic board repair, LCD TV logic board how much, LCD TV a horizontal line can be repaired