Laptop screen goes black when not plugged in

Repair of inverter black screen fault

1. Repair of Yaskawa ga700 inverter black screen fault. After replacing 3 electronic components, the display shows normal startup. The black screen of the inverter is mainly considered to be a fault of the switching power supply. There is a bad contact or short circuit fault, causing the switching power supply to not work properly. It will return to normal after powering on again, so the power circuit must be checked.

2. The black screen fault during Yaskawa inverter maintenance is usually caused by excessive damage to the inverter power supply voltage and internal short circuit of the IGBT. Replace it according to the IGBT model. If an internal short circuit of the IGBT is detected, first use a meter to test according to the IGBT circuit diagram, and then start the internal circuit of the module. After detection, the internal fuse fails to blow.

3. Yaskawa ga700 inverter black screen troubleshooting. After replacing 3 electronic components, the display shows that it starts normally.

4. Solution: Replace the voltage-reducing resistor. There is no display and a black screen is caused by the aging of the device. Solution: Replace the MOS tube, diode, and restore the inverter to work. The switching power supply circuit is not working properly. Solution: It is necessary to replace the damaged components to work normally.

5. A certain inverter has a fault and cannot operate and the LED displays "UV" (abbreviation for undervoltage). According to the manual, the alarm is DC bus undervoltage. Because the control circuit power of this type of inverter is not taken from the DC bus, but the control power is separately rectified from the AC input end through a transformer.

6. When the inverter is powered on, there will normally be a sound of the contactor closing. If there is no such sound, the contactor may be broken. If there is no problem with the contactor, check whether there is a problem with the power module. If the high-voltage power supply LED of the inverter is on, it means that the high-voltage DC power supply is normal.

Why does the laptop screen go black when the power is not connected?

If the AC adapter is unplugged, the computer screen goes black, unless the battery has been removed, usually the battery is broken (normal situation Next, unplug the adapter and the battery will power the computer. The computer can continue to be used normally).

It is recommended to send the complete computer to the official notebook after-sales service center, where professional maintenance engineers will conduct a comprehensive inspection, confirm the fault, and repair and replace it.

There is a problem with the graphics card or screen. If it works normally when plugged in, there may be a problem with the motherboard's power supply.

Check whether the chassis power interface and power cord are intact. If the interface and power cord are damaged or broken, they should be replaced in time. Check the motherboard power cord socket. If there is no damage, unplug the socket and plug it back in again.

Unable to power on, or the laptop battery is out of power, resulting in the inability to boot and a black screen. Solution: Replace the power adapter, or fully charge the battery. Bad contact of computer components Solution: Check whether the computer components (display cable, graphics card, etc.) are firmly and reliably inserted into the host interface.

If this happens to your notebook, here is a suggestion: Because you unplug the charger and use a battery with limited capacity, it automatically switches to power-saving mode and turns off the screen for a while. You can set it in "Control Panel" - "Power Management".

How to solve the black screen after unplugging the power of Windows 10 laptop

It may be a problem caused by the laptop battery. Remove the battery and only connect it to the power supply to use the computer to solve this problem, or give it a Replace the laptop with a good battery. It may also be a problem with the laptop screen. The probability of screen damage is relatively small. If you encounter this problem, you can only go to a professional for repair.

Solution: Unplug the memory stick and check it, then wipe it with an eraser; if it is a graphics card problem, you need to reinstall the graphics card driver; if there is a problem with the computer system, you can only reinstall the system. Solution to the black screen problem on the monitor: a. Check the host power supply to see if it is working properly.

Monitor: First check whether the monitor is normal. The method is very simple. You only need to turn off the computer or unplug the VGA cable of the monitor. Just turn on the monitor to see if there is no signal. If the monitor is normal, check the next step.

Black screen caused by software: Sometimes after installing some software or hardware drivers, you find that after restarting, the computer cannot enter the system and the screen remains black. This situation is a black screen on the laptop caused by software.

Check the power supply Please check that the power cord, transformer, extension cord, and wall plug connected to the computer are properly connected, as shown below. If the extension cord is equipped with a switch, please make sure the switch is on. Please be sure to use the original power cord and transformer with correct specifications to connect to the power port on the computer.

Asus laptop has a black screen when not plugged in

1. It is recommended that the complete computer be sent to the official laptop after-sales service center, where professional maintenance engineers will conduct a comprehensive inspection, confirm the fault, and repair and replace it.

2. This situation may be caused by insufficient battery power. It is recommended to try to connect the laptop to the power adapter for charging, and then try to turn it on to see if it can be used normally.

3. If the AC adapter is unplugged, the computer will have a black screen. Unless the battery has been removed, the battery is usually broken. (Under normal circumstances, if the adapter is unplugged, the battery will power the computer. The computer can continue normally. use).

4. Under normal circumstances, the notebook can be used normally after unplugging the power cord, but some users will encounter the problem of a black screen when the notebook is unplugged. Users who are troubled by this problem can refer to the following methods to solve it.

5. Asus notebooks have poor performance, and thin and light notebooks are not very durable. I use an ASUS, and it freezes every day. I do nothing every day. I don’t even use this computer card to watch TV series. I just do some PPT, some Excel, etc. As soon as I unplug the power, the screen goes black, and then plug it in again. Yeah, I guess the battery is not durable.

The laptop light is on even when the power is not plugged in, but the screen is black

1. The laptop screen suddenly goes black and the indicator light is still on. The reasons are as follows: Please try to increase the screen brightness and switch the display on and off to avoid The screen brightness is too low or the computer screen is black because the screen is turned off.

2. The reason why the Lenovo laptop's power button is on but the screen is black is that the computer may be in sleep mode. Try pressing the power button or the space bar on the keyboard to wake it up. If it is not in sleep state, there may be a bug in the system that causes the computer to freeze or freeze. Try to force shutdown and restart.

3. Reasons and solutions for the Lenovo thinkpad notebook power indicator light is on but the screen is not on: 1. Use a multimeter to check whether the socket is normal and whether the power supply voltage is 220V. If the mains voltage is not normal, it is recommended to replace it and test the usage environment. . 2. Use a multimeter to check whether the output voltage and current of the power adapter are consistent with the markings.

4. If the laptop screen appears black and the power light is on, here are some suggestions to try to solve the problem: Force restart: Press and hold the power button for more than 10 seconds to force shut down the laptop. Then press the power button again to turn on the computer. This can sometimes solve temporary problems.

5. It is recommended to use an external monitor of the computer, which is a general desktop monitor, and connect it to the external display interface of the notebook. If everything is displayed normally, the possibility of damage to the motherboard and graphics card is basically ruled out. Loose memory may also cause a black screen at startup. Users who do not understand are advised to take it to a professional repair shop for repair or send it for warranty.

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