hi good peep, I have a hp probook 4515s, it's showing a blank screen but the fan is on, the hard drive is running too fast, the lights are on, but it isn't giving any sign it wants to load the desktop.......pls I need a solution asap!.....thanks
Please do try a hard reset first, remove the battery and AC adapter then press and hold the power button for 20 seconds. Plug just the AC adapter then boot it up and see if it loads to your desktop normally and if it does you can put the battery back in as well. If there's still display after doing a hard reset but the fans and lights are on, connect an external monitor if available and see if you'll get any display from it because if you do there might be an issue with the display. Press the Windows key + P then select Display only then press Enter. If it still won't load that means it's the display.
If all these steps doesn't work you may need to contact the manufacturer for a repair if it's still under the factory warranty.