Can't connect two moniters at the same time

[TheExaByte]

Okay so today when i started up my computer my primary moniter wasn't working. It turns on during the boot but when it reachedes the log in screen it just says Displayport no connection and switched to my second moniter instead. So i tried a few diffrent things like restarting my pc and updating drivers and then i tried un plugging my second moniter and then all of the sudden my primary monitor worked. But whenever i plug in my second moniter the primary turns off so i can't have both connected at the same time.

All of this happend randomly i hadn't done anything to the computer and it's been running fine since i built it around 8 months ago.
I hope someone here can help me out and sorry if my english isn't that good.

 

[TheExaByte]

Update: it fixed itself now. don't know what the problem was but it seems fine now