液晶显示器的白屏故障的解决

液晶显示器的白屏故障的解决 LCD screen white screen fault resolution Similiarly White screen First, the white screen phenomenon shows that the backlight board can work properly, first of all, to judge whether the motherboard can work properly, you can press the power switch to see if the indicator lamp has any reaction. If the indicator light can change colors, it shows that the main board is working properly 1. check the output of the main board signal to the screen whether there is poor contact line (you can replace the connection line or screen) 2. check the voltage of each working point on the motherboard, especially the voltage of the screen 3. check the field signals and clock signals (from input to output) with an oscilloscope Two. If the indicator does not respond or does not light, it shows that the main board is not working properly 1. check the motherboard voltage of each work point, pay attention to the voltage of EPROM (4.8V), reset voltage (high level or low level, according to different models), CPU voltage. If the power supply short-circuit, fine Heart lookup short circuit position, there will be PCB plate copper foil short circuit possible 2., find CPU each foot contact with the motherboard is good 3. check whether the main board chip and the CPU work, and use the oscilloscope to measure whether the oscillation of the crystal oscillator 4. replace CPU or burn CPU when necessary ------------------------------------------- Author: Double sea computer The LCD screen we encounter is usually like this. Appear white screen fault, basically can be sure that the LCD screen power supply circuit more problems, that is to say, differential voltage. Liquid crystal display general works, LCD screen with electricity, and LCD screen without electricity should be white screen (we are such experiments, the LCD screen and the motherboard connection is removed, found the white screen). In the actual process of maintenance, we have two kinds of power supply screen, is a variety of screen working voltage is provided by the board, the other is the motherboard provides only a 3.3V voltage, the voltage of various other screen is required after the circuit board screen. If it is the first mode of power supply, the difficulty of overhauling the motherboard is relatively small, and the relevant information is relatively large. If it is the second way, in general, the LCD screen is to be scrapped, the overhaul of the difficulty is quite large. Except for the factory, the maintenance data is basically not available. Under normal circumstances, the LCD screen required for a variety of operating voltage 3.3V, 10.V, -6V, -18V and several other, we overhaul the main check is 10V, -18 (-6), V two sets of voltage Upload time: 2007-07-24 13:46:35 C White screen because the backlight normal screen is not properly received, the motherboard sent the signal on the white screen. This shows that the high pressure part is good. There may be no power supply motherboard is not working properly, there may be a screen line not connected, re inserted a look. There is a possibility of screen on the back of no power supply, look at the screen to screen the power line interface has no open insurance. ------------------- The main check to the screen power supply, white screen, in general, cable will be good. Or is the program dropped, it will be like this ------------------- Screen only shows the signal, and now the screen does not work, there are two possibilities. One is that the screen is scrapped, Another possibility is the voltage supplied to the screen, the voltage is 0, that is, the screen line may be broken, or there is a safety circuit broken, or a power supply circuit damage to a capacitor. It's possible. The best thing for you may be that the safety circuit is broken, so that the repairs will cost only 20 yuan. If the screen doesn't work. You'll have to pay more. Employed Or look at the power, 3.3V, 5V are normal, if the MCU voltage is not 5V, or a lot of lower, it will turn on the wrong And Backlight is off. LCD controller is off The interface of the line from ----------------PCB to panel is generally not solid and easy to loose, which will cause this problem ===================================== BenQ LCD FP72E boot white screen for a few minutes Fault phenomenon, a BenQ LCD model is FP72E, boot normal, a few minutes after the white screen, the shutdown is reopened, both normal, and a few minutes later will be white screen, measuring AD board 5V, 3. 3V power supply has been normal, AD board on the MCU crystal measurement, suspected MUC work is not normal, but there is no basis.. Because there is no data, the data is decided. If it is the power supply on the screen, why is it normal to shutdown again?. I do not know from the MUC work status or start directly from the screen board power supply, there are only two pieces of IC on the screen board, there is a piece of PWM Inspection process and fault analysis 5V power supply panel is normal, PWM can continue to provide voltage to the screen, and the AD board of the MCU does not work, no D-SUB treated by IC after converting the signals to the panel on the screen, so at that time should be no display but not black or white screen, can keep the white screen and open MCU turn signal to the pressure plate, or even the screen is not bright. The PWM above the screen board is very small, the model is AAT1164, the heat is great, look at the circuit boards are hot discoloration. And later on the Internet to find AAT1164. Name: LCD high voltage chip, the chip for LCD screen, high voltage generation and management chip, BenQ LCD often bad, fault: white screen. Model: AAT1164 Brand: AAT Package: QFN M170EG01 new screen common problems, mainly used in BenQ FP71G+ LCD display above. With a period of time will be white screen, shutdown, in use for a period of time and appear white screen. This IC is really easy to bad, mainly because of the temperature is too high. The fault phenomenon for the normal boot, with a period of time white screen. Touch the chip surface temperature is very high Partial circuit diagram with fault Maintenance plan and result, replace AAT1164 after 2 hours, trouble shooting! Maintenance costs 120 yuan ========================= Maintenance example of DELL15 inch LCD The fault phenomenon can be switched on, and the host is full screen, but the menu shows normal. This kind of flower screen is not the kind of flower screen with insufficient resolution, but is very like the stripe of a kind of calico. Open the case analysis process and fault detection, the measured voltage is normal, as measured by 3.3V, the voltage is 1.25V, the measured power point to ground resistance, the discovery of approximate short circuit, and very hot, this phenomenon is very strange, almost can short circuit output voltage of 1.25V, This phenomenon is seen in the motherboard, did not expect in the liquid crystal display also appeared, regardless of these, to find the line, finally found this voltage to the control chip power supply, in some small measure around the chip when filtering is short, so some may doubt the chip internal short-circuit welding. Under the chip measuring small capacitance across the resistor is very small, indicating that the chip is no problem, the small capacitance must have a short circuit, and one welding measure, welding only several to be found, is indeed a small short circuit with capacitor filter capacitor, the same color and size of the generation after the fault excluded. Partial circuit diagram with fault Maintenance program and result replacement control chip power supply filter power after repair Maintenance costs 60 yuan ======================= Power up, indicator light green, dark screen (in the light, carefully, vaguely, images). Detection process and fault analysis, this kind of fault is usually the backlight of the display, no work caused. Disassemble, found this power board and the pressure plate is integrated. Focus on the high pressure plate section, found that two C5707 switch tube breakdown, and then go up to find a 9024 of the pressure tube also breakdown, and then go up and found a 12V power supply, insurance resistance also burned. Thus, replace the above components. On line power up, showing normal. Partial circuit diagram with fault Maintenance program and result of replacement of two C5707, one 9024, one safety resistor after normal. Maintenance costs 80 yuan ======================= LCD screen white screen? My monitor is started from the start, with more than 2 hours to start the white screen display, the top temperature is very high, this is the monitor and turn it on again good, and then a few minutes a white screen, more and more frequent. If you turn on the light, browse the page for about 4 hours before you start the white screen. If you play the game on the computer, you'll start the white screen for 2 hours. Is this a display problem or a video card problem? If it's a monitor problem, can you fix it? How much will it cost to repair? Monitor model BenQT705, Beijing, where are the maintenance points? Urgent urgent!! Seek expert help. 1: the screen line is bad, the possibility is small 2: the driver board is bad, there is possibility 3: the screen is bad, the possibility is great The LCD board is out of order, and the circuit board is deformed after heating, which leads to the abnormal connection of the circuit. Only when the factory is renewed, the service station will not be able to repair it I also have a similar to you, support for a few months, and now scrapped!! Said that the screen is changed, can not be repaired!! If you are still in the warranty period, change or repair it immediately! ========================== Samsung 710/510 LCD display "non optimal mode recommended mode [email=1024*768@60HZ]1024*768@60HZ[/email]" did not display or signal automatically after the black screen not to signal is displayed when no signal input. ". The main reason of the common fault detection process and the fault is caused by the MPU data error Samsung 710/510 LCD display, general computer market in Hangzhou have been written into various types of Samsung MCU program chip sale, as long as the original main control board on chip, replace the new chip program has a good brush this failure can, on the bottom. To solve the penetration welding chip, Note pad position and direction of the pin of the chip and the main control board of the chip must be welded after replacing the MCU online charging, troubleshooting. Partial circuit diagram with fault Repair program and result, replace MCU program and chip after troubleshooting Maintenance costs 60 yuan ====================== MAG 19 inch LCD display XP911V0 without electricity, light does not display no response. The detection process and the fault analysis and disassemble, found this liquid crystal display there are two plates, one is the integration of the power plate pressure, the other one is the main control board. On the market, the power supply board has 5V for powering the main board, and 12V for supplying power to the high voltage board. Re test, the main control board linear voltage regulator block 1084 of the middle foot 3.3V normal. This shows that the power board and the main board power supply is normal, the problem in the main board of the control circuit. General master to normal work, first of all, there is a clock signal, then add power to measure the voltage of the crystal pin, the hot pen touched the crystal foot, the panel indicator light. This shows that the crystal is not good, the main control can not shake. Thus, the replacement of KTS14.3J2B, after the switch to open the key several times are normal, 6 hours of copying machine, there is no problem, fault repair Partial circuit diagram with fault Maintenance program and result, remove the main chip after the crystal oscillator, troubleshooting Maintenance costs 80 yuan ==================== LCD screen Post By:2007-7-29 14:21:00 white Li Pu LCD, 170S5 white screen, 5V and 3 screen. The normal 3V DCDC converter didn't work no 20 volts and negative pressure, the type is AUO M170EG01 V1B screen no drawings, which master repair testing problems, help, screen circuit drawings words to me, thank you very much for 1, 2, 3 feet, VCC 5V. 4, 5 feet GND. 6 feet, 10V. 7 feet, 23V. 8, 9 feet GND., 10 feet -7V., after detection voltage, this machine's OUT terminal voltage is 0V. Make sure 9743A is bad. Upstairs seems to be wrong, my BA9743A information and how you are not the same, 7, 10 feet output, 9 feet VCC, 8 feet GND, 16 pin package The power supply is not =================== screen problem ah!! There are two positive voltage on the screen display circuit, one way negative voltage to see if there is any fault What's the problem with =====================dell E151FP using a white screen for a while? I ran into several, and there was a screen flashing The component has poor thermal stability Check the inductor, remove the oxide is generally not net,. Many repairs have been made The main problems in power supply, reason is the pressure plate. This is a common problem The main problems in power supply, reason is the pressure plate. Is an inductive screen for weld power supply circuit board in the LCD screen white Pinghua fault diagnosis and maintenance (screen fault collection) For the flower screen fault, to judge whether the screen is bad or drive bad, I am like this! There are different opinions, everybody points out! 1 Huaping repeated after power on, the flower color stripe, change the drive plate -- more bad 2 Huaping repeated after power on, the flower color stripes, no change - screen itself more bad Of course， Finally, we also have to change the drive panel test screen, but it's enough for the bad LCD monitor. It won't suffer too much because of the bad screen! In fact, a lot of flower screen problems, it is best to explain the screen model, because there are a lot of screen itself is prone to problems! For white screen, of course, have to check the quality of the next screen on the good or bad! for example 1: HT17E12-200 main IC:TFP7433PZP bad white screen for most of the good, flower screen like a blue background stripes, after the failure of the same! 2: LM170E01 IC:SN0209033PZP white screen for the most good, Huaping change showed a bit empty, each for several hours after bad 3: Samsung screen with IC LXD91811, less color, flower screen, and so on, as long as the chip is no problem, change all can be good! LXD91811 can be substituted for LXD91810 And LXD91812 4: M170EG01 (old) IC:AUO-003 AS-F15 Pinghua white screen AS-F15 cache overheating capacitor C99 C100 has a bad change. Just fine. I'm not bad when I fix it, AS-F15 5: TX38D14VC0CAA black bar fault has not been solved 6: HT15X15-D01 black Kennedy fault (black bars spaced) too 7. M170EG01 (New) flower screen, white screen is bad, AAT1164 change is good, did not touch, change, and then out of other problems 8., M190A1 flower screen, lattice, slow response, slow reaction of main IC:CM2709 and screen screen change, in the 80% grid has not been repaired This problem I repaired, is the voltage detection part of the two field effect transistor, damaged the specific model, forget the voltage comparison, after the change on the OK Should be the circuit board to the LCD screen between the LVDS line may be a bit of a problem, if there is a condition to open to see, no condition to change, not expensive The white screen indicates that the power supply is good. It may be a video processing board. Because there is no signal output, the LCD screen doesn't show anything. 1) video processing board fault, the trouble may be professional maintenance personnel for maintenance; 2) loose on video board video output cable, video signals can not be output, it was resolved, the joint re install it... Check the interface of the monitor. If you start this one, try another monitor LCD white screen, is a common fault, this will open your LCD back, look at your PANEL cable is loose, this place will often loose, look at it, if it is tight, it should be sent to the maintenance department to repair. If you are a professional, you don't have to. ) I am a professional, and I will show you if I am here. High pressure doesn't matter! 900v current is very low and the electricity is not dying. I am often supplied by the electric light which supplies power to the liquid crystal tube. But the power cuts must be ok! It is estimated that the driver plate is not broken, that is, the screen line dropped, you check, if the screen is broken, it will be finished! Drive board price also dies 20-30 yuan! When the screen is broken, there is no need to fix it