Why is my laptop screen flickering in black and gray?

Question

Iron

Hello!
Tell me please, the screen of the laptop began to flicker after the start, and it enters the BIOS normally, and the HDD blinks (as usual at startup). Nothing is visible except this flicker (black-gray change).
I ordered a cable for the matrix, I still distrust the cable of the hard drive (quite flimsy).
When you press esc, the boot menu pops up.
I connect the second monitor and nothing.

Answer 1

Something with the hard drive, tk. I inserted the flash drive and booted from it normally.