Laptop won't turn on, flashing lock icon

Hello everyone,
I have an HP laptop (I don't have the model) lent to me for studies, but since this morning, when I try to turn it on, the power light comes on, but the screen and the computer do not (no sound). Moreover, the Caps Lock key light (padlock) blinks 3 times in white light, then goes off and blinks again, and this goes on infinitely. No forum discusses this issue, so if anyone can help me, I would appreciate it.