Cyclic restart of the PC when connecting a video card, how to fix it?

Question

Iron

ga-g31m-es2l REV 2.0
gv-r777oc-1gd
It used to work, at startup with the installed drivers it gave a black screen (I think the problem is in the power supply), but now it does not start at all.
When turned on, 1 beep comes out and restarts, does not display an image and does not respond to NumLock at the start, what could be the problem?
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At the moment I have a post card and other iron to test.

Answer 1

Lack of PSU power.

Answer 2

look at the primary adapter
and the capacitors in the power supply unit at 12 V