[Beginner] ThinkPad T460 won't boot - flash BIOS-chip?

Hello there,
this is my first post to the forum without any prior knowledge to flashing or the BIOS in general.

So here is the explanation of my problem:
I’ve bought a used ThinkPad T460 as a defect unit. It has an i5 Chip, 4GB of RAM and a 500GB HDD. When i press the powerbutton the unit starts and the screen activates (only black pixels, nothing is shown). If i wait long enough the system powers off and on again in a loop. I’ve uploaded a video of the process to YouTube:

I have also posted to the ThinkPad Forum and Reddit. The folks on reddit suggest flashing the BIOS-chip or buying an entirely new Motherboard. I’m eager to learn new things, so i’m willing to try my luck in flashing the chip, but i don’t know yet how to proceed from here.

Am i even on the right track? Has anyone of you had the same/ a similar issue before?

I’m glad to here from you!