Hi!
Did you tried a hard reset first?
Please remove the charger from the laptop. Then do the following:
* Make sure that the laptop is off.
* Hold the power button for 20 seconds and then release the button.
* Wait 10 seconds.
* Now press the power button 1 time.
Now it should boot up again (this can take some time and it’s normal that the LED is flashing).
After this, make sure you download and install the latest BIOS version.
If this failed, you probably need to replace the motherboard to get it working again.