Sembra si tratti di un'avaria hardware che non consente di effettuare il boot, probabilmente la RAM :look:
Potrebbe essere utile seguire questi passi suggeriti dalla stessa HP:
"Reset the laptop to attempt to resolve a blank screen. - Press and hold the Power button until the laptop turns off, and then disconnect any cables, including the power adapter. - If your laptop has a removeable battery, slide the battery release latch, and then remove the battery. - Press and hold the Power button for 15 seconds. - Reconnect the power adapter to the laptop and a wall outlet, but do not reinstall the battery, if you previously removed one. - Press the Power button to turn on the laptop. - If the screen remains blank, continue to the next step. - Test the laptop video card by connecting to an external monitor or television, if you have one available. - Connect an HDMI, VGA, or DisplayPort cable from the laptop to the external monitor or television. - If the monitor or television remains blank, press the F4 key or the Function and F4 keys to switch the display to the external monitor. - If the monitor or television displays correctly, go to hp.com/drivers to install the latest graphics drivers for the laptop to fix the blank screen issue. - If the screen remains blank, disconnect the cable used to connect to the external monitor or television, and then continue to the next step. - Recover and install the last working version of the BIOS. - During this process, make sure the laptop is plugged into a wall outlet. - Press and hold the Power button until the laptop turns off. - Press and hold the Windows and B keys, then press and hold the Power button for one second, and then release all three. - The Power LED light remains on, and the screen remains blank for about 40 seconds. - If the HP BIOS Update screen displays, the issue is resolved. - If the screen is still blank, continue to the next step. - If your laptop has a panel to access the memory, reseat the memory modules to make sure the connection is secure. - Disconnect the power adapter from the laptop and power source. - Press and hold the Power button until the laptop turns off. - Remove the access panel and set it aside. - On each memory module, push out the two securing latches to release the module, and then slide it out to remove it from the computer. - Avoid touching the metal contacts when handling the modules. - Reseat the module in the bottom slot, and slide it into place. - Push down on the module to lock the two securing latches in place. - If equipped, repeat this process for installing the second module in the top slot. - Reinstall the access panel. - Reconnect the power adapter to the laptop and a wall outlet. - Press the Power button to turn on the laptop. - If the screen displays, the issue is resolved. - If you previously removed a battery, turn off the computer, reinstall the battery, and then turn the laptop back on."
Per alcuni di questi passi sono necessarie la rimozione della batteria e l'apertura del laptop.
Spero possano esserti d'aiuto ;)
