@kamenov Welcome to HP Forums, this is a great place to get support, find answers and tips, Thank you for posting your query, I'll be more than glad to help you out 🙂
As I understand the computer is not turning on or is displaying only a black screen,
Please perform the below steps:
If the computer does not start, the LED lights do not glow, and the display is black, you can perform one or more of the following actions to resolve the no power issue:
(Click on the blue letters to get more details about each step)
Examine the adapter and power cord for physical damage
Test the power from the AC wall outlet to the notebook connector
Start computer using the battery only
Check that the lid switch moves freely
When you have completed the troubleshooting steps covered in this document, there should be power available to the computer. When you press the power button, the LEDs should glow, and you should hear the sounds of the fan and the hard drive spinning.
If the battery does not accept the charge or the notebook does not turn on without the AC adapter, contact HP to order a replacement battery.
If the LEDs do not glow, and there are no other indicators of power being available to the computer, contact HP for technical assistance in troubleshooting a potential problem with the AC power connection or the system board.