The notebook is turned on without any display reason.

When the laptop is turned on, there is no display reason "The laptop battery is dead-or the external AC power supply is damaged-or the power supply is poorly connected.

Power cord problem

Please check whether the power socket and power cord are normal.

Chassis power problem

Please check whether there is a standby voltage of 5 volts and whether the connection between the motherboard and the power supply is loose. If you can't measure the voltage, you can find a power supply to change it.

Main board problem

If there is no problem with the above two points, then the possibility of motherboard failure is relatively large. First, check whether the connection between the motherboard and the power button is loose and whether the switch is normal. You can try shorting the switch with wires. If it doesn't work, we must try to replace the motherboard.