Question Monitor going black for a couple of seconds

Laughskate

Great
May 20, 2020
117
4
85
I still have not received help yet on this case. Basically whenever I use my computer my monitor goes black randomly for 3 seconds. I have used the same vga cable and monitor on another pc and this issue does not happen. In my current pc I have a adapter (I don't know what it converts from to vga, I got it a long time ago.) and use the same vga cable and monitor and somehow a black screen happens for a couple of seconds. I don't know why this is happening and I could really appreciate if someone helped me. Also 1 port of the rx 580 doesn't even work which is strange.
Specs:
Cpu: i5 4570
GPU: msi rx 580 8gb
psu: 550w (don't know brand)
ram: 2x ddr3 8gb
os: windows 10 pro
 

Laughskate

Great
May 20, 2020
117
4
85
Whenever I start my monitor and pc when I log in to windows after a couple of seconds the monitor will go black for like 3 seconds. It occasionally happens while gaming. Why?