As soon as the laptop is turned on, the screen flashes one bright and one dark like voltage instability. How can I just run for a while?

Was it plugged in when it was used before? Just before this time, for example, yesterday, you plugged in your laptop and used it for a long time, so the battery was low. This may happen if you use it again today, and sometimes it won't start. You can try this, unplug the power and see if the battery in the lower right corner is full. If it is full, please turn off the computer and take out the battery. Then press the power button (note that it is not plugged in and the battery is not installed). Then install the battery, plug in the power supply and turn it on to see how it reacts. If everything is all right, then you can use it first. Do it again after using the computer at night, and then wait until tomorrow morning to see the effect. If there is one bright and one dark, it means that the temperature difference is large. That is, the weather is too cold. This problem can be solved.