Why do video cards die?

Question

Iron

The problem is this:
I assembled a computer from new components, with the exception of the video card. Everything worked great for 3 months. After that, the video card began to turn on every other time, constantly blinking backlight, the screen did not turn on. After that it just didn't turn on.
Having made a mistake on the video card, I sent it under warranty (it is still in the store, but there are other questions), there is no diagnostic result yet.
After spending a week without a computer, I realized that this was not an option, and again bought a "temporary" used video card.
She did a great job despite her age. A week later, a new problem: in any game or furmark, the computer freezes tightly (only reboot helped, it did not respond to any keys). I thought that the video card was overheating, forcibly turned on 60+% of the fan in the afterburner.
But today, instead of the usual freeze, the computer clicked and turned off.
Bottom line: the video card does not turn on, there is no burnt anywhere, the unit is in perfect order.
Question: why do video cards die?
Hardware:
Ryzen 2600x
MSI b450 tomahawk
Gskill 2x8gb ddr4-3000
Samsung 970 Evo plus 500gb
Chieftec a90 750wt
Gigabyte g1 gtx1070/ AMD r9 290x

Answer 1

power supply gomno

Answer 2

Try to monitor through hwinfo64, include the log in a file and load the video card with a test
. I have a Gigabyte g1 gtx1070 from the start of sales, it works ~ 2 years under manual overclocking

Answer 3

Check the voltage and its stability from the PSU. Or if there is no additional power, then from the motherboard to the video card. Maybe the problem is with her?