Asus K501UX does not boot

After 2 years of moderate use, my Asus K501UX - Win 10 suddenly showed a blue screen, stating (my translation, the original was in Spanish, see image below):

"Recovery

The hardware or device needs repair

The header verification checksum of this file does not match the calculated checksum.

File: \windows\system32\winload.efi Error code 0xc0000221

You should use recovery tools. If you do not have installation media (as a DVD or a USB device), contact the administrator or the manufacturer of the equipment or device.

Press Enter to try again Press F1 to go to the recovery environment Press F8 for the boot configuration Press ESC for the UEFI firmware configuration"

After that, I turned it off (by pressing the power button for >10sec). Then when I turn it on, the green battery light keeps blinking, with a dark screen. Nothing else happens.

Any ideas on how to solve it?

PS: I was in doubt whether SuperUser is an appropriate site for this. Reading this suggested me it is.