HP ProBook 440 G11 will not turn on or start

The checks in more detail

If the laptop turns on but the screen stays dark, shine a flashlight at the display to see a faint image, which would mean the backlight, or connect an external monitor to learn whether the graphics work. Now open the start-up menu. Press the power button and tap Esc repeatedly until the menu appears. HP lists its options by function key: F1 shows system information, F2 runs System Diagnostics, F9 chooses the boot device, F10 opens the BIOS setup and F11 starts System Recovery. Choose F2 and run the quick test of the drive, memory and battery;

a pass on all three suggests the hardware is sound and the fault is in Windows or its start-up files, while a failure comes with an ID that HP will ask for. In F10, check the date, the boot order and that the drive is listed. A missing drive means a loose or failed drive, and the boot order showing a USB drive first means a stick left in the port is stalling start-up. If the hardware passes, F11 System Recovery restores Windows from HP's recovery partition, which can keep or erase your files depending on the option, so back up first if you can.

Alternatively use Windows' own recovery for Startup Repair or System Restore. A ProBook bought through a company may be enrolled in management, so ask the IT team before using recovery, since a reset can lock it out. HP Sure Start, a BIOS protection feature on business models, can repair a damaged BIOS on its own and may make the laptop restart once or twice at power-up; let it finish. If nothing in the start-up menu works, the screen stays dark and the lights do not respond to a charger, contact HP with the serial number and product number from the base.