Power light ON but never turn On

@aukisuper which LED lights up when you connect your AC adapter? does it blink in a pattern or does it blink continuous. Continuous blinking is usually a bad thing, since it is most common a motherboard issue. Not that it can't be repaired but it just is more complicated work since it will require a board-level repair.

For now, try a reset first:

1) Remove the battery and unplug the DC power adapter.
2) Press and hold the power button for more than fifteen seconds.
3) Plug in the DC power adapter (leave the battery out for now)
4) Press the power button

If that does not work you will have to start at the beginning for some troubleshooting.

First you want to check your power supply. Make sure it has the proper voltages. Check to make sure that connectors are not bend etc. Check the DC-in jack of your laptop. Make sure there is no corrosion, debris etc. that prevents it from working. Clean it of any debris etc, use a few puffs of air to clean it out. If none of this works, get an ammeter and see if your laptop draws any amperage from the charger. After that, you need to check and see if your motherboard even gets power. For that of course, you need to open it up. Post Some good pictures of what you see. That way we can see what you see. Use the Hp Probook 450 G7 Maintenance And Service Guideto work on it. Let us know what you find out.

Adding images to an existing question