Help: My LCD is not working

If there is a white screen failure, it is basically certain that there are more problems with the power supply circuit of the LCD screen, that is, the poor voltage.

The working method of the general LCD display is that the LCD screen works after powering on, and the LCD screen should be white if it is not powered on (after removing the connection between the LCD screen and the motherboard, a white screen is found).

In the actual maintenance process, there are two types of power supply methods for the screen, one is the various working voltages provided by the motherboard, the other is the voltage provided by the motherboard, and the other voltages required by the screen are provided by the circuit board behind the screen.

If it is the first power supply method, the difficulty of overhauling the motherboard is relatively small, and there is more relevant information.

If it is the second way, under normal circumstances, the LCD screen is to be scrapped, and the difficulty of maintenance is quite large. Except for the factory, there is basically no maintenance information.

Under normal circumstances, there are several kinds of working voltages required for LCD screens, and we mainly check the two sets of voltages of 10V and -18 (-6) V when we overhaul them.

Let's see if you can enter safe mode, if you can, the graphics card refresh rate and resolution are out of range, you can uninstall the graphics card driver in safe mode, and install it in normal mode.

Your monitor is faulty in the signal transmission part!! It should be repairable, but I'm afraid I can't get it myself! Or go to the maintenance staff.

Change a monitor first, see if it can be normal, I also think it's the refresh rate and resolution out of the range, then change a monitor and then enter safe mode to adjust it.

The signal board (ad board) of the display is broken, and I need to replace it, I repair the monitor, and I see a lot of this situation!

Your LCD is not voltage enough, or the lights are broken.

The monitor is hard to fault, go and replace. Hard tone.

I guess there's something wrong with the monitor's tube.

Can it still be done after the function?

Can it still be done after the function?

Whether the power light of the host is normal or not, if it can be displayed normally, the power supply problem will be ruled out, otherwise the power supply will be replaced.

1. First disassemble the shell of the LCD display, and then check whether the screen cable interface is loose or not connected. After checking, the screen cable is connected normally.

2. Then open your laptop.

The power switch , and then use a multimeter.

Measure whether the power supply voltage of the screen cable interface is normal. If the supply voltage is normal, go to step 5; If it is not normal, then check whether the fuse resistor or fuse inductor near the output of the screen cable is open or damaged. If it is damaged, the damaged component can be replaced.

3. If the fuse resistor or fuse inductance near the output end of the screen cable is normal, then check whether the output voltage of the DC-DC voltage conversion circuit supplying power to the LCD display is normal. If the output voltage is abnormal, check the fuse resistor, PWM controller, switch, and inductor coil in this power supply circuit.

Filter components such as capacitors, and then replace the damaged components.

4. If the voltage at the output end of the DC-DC voltage conversion circuit is normal, there are damaged capacitors and other components between the output end of the DC-DC voltage conversion circuit and the interface of the screen line, and the damaged components can be checked and replaced.

5. If the power supply voltage of the screen cable interface is normal, then check whether the timing signal and drive signal in the drive circuit of the LCD panel are normal. If it is abnormal, check the output signal, input signal and power supply voltage of the chip that generates this signal respectively to determine whether the driver chip is damaged. If it is damaged, it can be replaced.

Summary. Hello dear, the solution to the computer display screen not working is as follows: 1. Check the wiring of the monitor, no problem, just borrow someone else's monitor to try or move the monitor to someone else's house to try.

2. Check the memory module, you can take your memory module to another machine to try it, or borrow one to try. 3. Confirm that there is no problem on it, it is the motherboard, and send it to the computer city to repair the motherboard, about 30 yuan. If not, change the motherboard or add a discrete graphics card.

What to do if the computer display is not working.

What to do if the computer display is not working.

Hello dear, the solution to the computer display screen not working is as follows: 1. Check the wiring of the monitor, no problem, just borrow someone else's monitor to try or move the monitor to someone else's house to try. 2. Check the memory module, you can take your memory module to another machine to try it, or borrow one to try.

3. Confirm that there is no problem on it, it is the motherboard, and send it to the computer city to repair the motherboard, about 30 yuan. If not, change the motherboard or add a discrete graphics card.

Extended Information: Computer monitors are also commonly referred to as computer monitors or computer screens. It is the most important computer component in addition to CPU, motherboard, memory, power supply, keyboard, mouse, and is a display tool that displays certain electronic file information on the screen through a specific transmission device and then reflects it to the human eye.

Computer monitors are divided into two categories: LED displays and LCD displays. The failure of a computer monitor is divided into soft and hard failures.

Extended Information: From the early world of black and white to the world of color, computer monitors have gone through a long and arduous journey, and as display technology continues to develop, the classification of displays has become more and more detailed.

The LCD machine has no power is one of the phenomena in the display screen failure, the LCD machine has no power is the display is powered on and there is no display, and the LCD is powered on and does not show how we should repair it? Next, I will tell you about the maintenance of the LCD display without display failure when it is powered on in two situations.

Step 1

1. The power failure of the display is not displayed when the display is powered on

This is a very simple fault, the general LCD extension internal power supply and external power supply, the external one is more common. Regardless of the power supply, its structure is much simpler than the power supply of CRT display, and the vulnerable ones are generally some small components, such as fuses, rectifier bridges, 300V filter capacitors, power switches, power management ICs, rectifier output diodes, filter capacitors, etc.

Second, the display is powered on and there is no fault of the driver board of the display

If the driver board burns the fuse or the voltage regulator chip fails, some machines have a built-in switching power supply and output two sets of power supplies, one of which is 5V for signal processing, and the other is 12V for high-voltage board point backlight.

1. If there is a fault in the circuit of the switching power supply, it may cause the two groups of power supplies to be not output, first check whether the 12V voltage is normal, and then check whether the 5V voltage is normal, because the working voltage of the MCU chip of the AD driver board is 5V.

2. If you find the fault that can't be turned on, first measure the 5V voltage with a multimeter, if there is no 5V voltage or the 5V voltage becomes very low, then there may be a problem with the input stage of the power supply circuit, that is to say, there is a problem with the power supply part of the 12V to 5V conversion, this fault is very common, check the 5-end stabilizer block.

After the 5V voltage returns to normal, it cannot be turned on normally'On the one hand, the MCU's program is flushed out and may not boot, and the MCU itself is damaged, for example, the MCU's I-O port is damaged, so that the MCU can't scan the keys, and when encountering this kind of fault caused by the MCU, it is useless to find the problem of hardware, even if you change the MCU, you can't solve the problem, because the MCU needs to be programmed and coded, and in the case of no way to find the original AD driver board to replace, we can only use General A d driver board substitution, such as: 151d or 161b, etc.

3. Another possibility is that the 5V load is heavier, and the 5V voltage is pulled very low, that is, there is a problem with the signal processing circuit of the rear stage, and some circuits are damaged, causing the load to increase. Pull the 5V voltage very low, check the components that have problems in the rear stage one by one, and replace the faulty components, the 5V can return to normal, and the fault is generally solved.

1. Black screen failure and fault phenomenon:

After booting, the host does not have any error indication on the display, and the status indicator of the display is normal, and the power switch is also normal, but there is no image (black screen), but sometimes it can be displayed normally when the color display case is slapped or occasionally turned on, but the situation is getting more and more serious after using it for a period of time.

Second, the misunderstanding of the fault point:

This fault may seem to be the result of a poor contact somewhere in the circuit, but many people often don't know what is causing it.

3. Causes and countermeasures of failures:

1. You can first look at whether there are virtual soldered components or solder joints in the filament power supply circuit, which is usually the culprit of such failures.

2. Sometimes the host will also cause a black screen due to the host, but no matter how you slap the color display case, it will not get better, so if you have the conditions, you can connect the monitor to another host to determine that there is no fault to try it. In addition, there are many displays at present, after unplugging the signal cable connected to the graphics card, the self-test display function will appear, if the display is normal, it means that the display is basically fault-free, and the fault point is on the signal line or graphics card, so that it is more convenient to find the fault point.

Note: In view of the fact that the failure causes of other black screen phenomena are relatively professional, they will not be introduced.

Desktop computer boot monitor no display troubleshooting.

First check whether there is a problem with the display, dial the signal cable from the host, turn on the power of the monitor, and see if there is a prompt on the screen that shows no signal, if there is, it means that the display is fine, and the rest is the problem of the host. Turn on the power of the host and listen carefully to whether there is an alarm sound, the alarm sound is different, and the fault is different.

2 Short There is a problem with the general settings, please go to CMOS and reset the incorrect option 1 Long 1 Short RAM or there is an error with the motherboard. Try a different memory.

1 Long 2 Short Monitor or Graphics Card Error, Detect Graphics Card and Monitor 1 Long 3 Short Keyboard Controller Error. Check the motherboard and contact the merchant.

1 long 9 short Motherboard flash RAM or EPROM error, BIOS corruption. Contact the merchant and try a different flash ram.

If you can't hear the alarm sound, remove the memory, turn on the power of the host, and see if the alarm is given, if it still doesn't, there may be a problem with the motherboard, it is recommended to take the motherboard to the computer company to check it.

There are more things with a display screen, and the ghost knows what you're doing?

Hello, this phenomenon occurs, there are two possibilities, 1 is the failure of the display high-voltage board, 2 is the failure of the display tube, the failure of the display high-voltage board: if there is a voltmeter, and you will use it, you can disassemble the display, measure whether the voltage of the high-voltage board output to the lamp of the screen is normal, the normal working voltage varies depending on the type of screen, the LED screen is basically 30 55V, and your phenomenon should be caused by the LED screen. If you don't have the conditions, it is recommended to go online, or a repair shop to buy a second-hand general high-voltage plate to replace it, **It should be around 50.

Display lamp failure: Eliminate the high-voltage plate fault, then only the lamp failure of the display screen. The lamp cannot be repaired, only replaced.

You can go to the repair shop to see if there is a replacement, if the repair shop does not have the same type of lamp replacement, then you can only replace the display. There is a model number written on the back of the display, which can be bought and replaced by the electronic store or online according to the model. ps：

The display is very high, and the cost of a new display accounts for 70% of the display, so it is not recommended to change to a new screen, which is not cost-effective.

If your monitor is within the warranty period, you can directly find after-sales, don't repair it yourself, otherwise the after-sales service will not be warranted.

In addition, if you want to analyze it yourself, you will need to disassemble the machine, you can disassemble it as follows:

Prepare a plastic piece first, such as a discarded bank card, membership card, etc.

Remove all visible screws first.

Insert a card from the border, then pull down the gap to make the gap wider. until the entire back shell can be pulled up.

Note: If you don't have the equipment, or lack the hands-on ability, it is recommended to send it directly to the repair shop. Like general computer repair shops, home appliance repair shops can repair them.

This is an LED backlit display, and the more likely reasons for this phenomenon are:

The LED chip burned out - the display needs to be disassembled and repaired.

LED driver loop IC failure – can be fixed by simply dismantling the display housing.