My laptop screen can't come up. The power indicator lights are on, and the fan is working

[Uche19]

Hp probook 6570b 

[Jupitero]

Hello.

If you press the caps lock button, does the caps lock led toggle on/off? If it seems to work normally, the display panel is faulty, or the internal display cabling has disconnected from its connectors or the cable itself is faulty.

Try connecting your laptop to an external display via DisplayPort or VGA port. If your computer starts normally into Windows, try looking very closely at the laptop display while moving e.g. a whole window or mouse cursor or producing some other movement on the screen. Do this in well illuminated area. If you can actually see the movement (very dimly), the display panel backlight is the culprit and the only fix would be to replace the whole panel.