What could be the reasons for bios failure?

Question

BIOS

What is the question on two computers connected to the same local network with a difference of several months, BIOSes have been very thorough.
Paranoia says that something is wrong here, since there is also a third computer outside the network on which the bios also falls (but it is really very old).
So the question is what, in principle, can cause a bios failure? Power supply, virus, computer age, what else?

Answer 1

Let's just say what you wanted to say with this phrase "bios have completely blown off."
BIOS settings can fly off because they are dependent on power supply, batteries,
but the BIOS itself will be available and you can configure and boot the PC again,
there are options that the memory chip that contains the BIOS is flying. it's rare but it happens