Question pc booting problem

[Aarifter]

my pc doesn't start up right after shutting down, i have to remove the cables, reinstall the gpu, and keeping turning it on or off. then finally it starts up , plz help me

 

[PC Tailor]

Please post full system spec including PSU make and model.

What have you tried?
What exactly is it that seems to cause it to turn back on?
Did anything happen when it shut down?
Have you monitored temperatures of CPU and GPU?

 

[Aarifter]

i dont know i reinstalled the graphics card once it booted, i also removed the cable once and let it rest. that also worked but when i go to do these things agin it doesnt boot up
my pc is Dell Optiplex 3020 i only have installed a gtx 750