HELP, monitor/gpu problems

[codenameveg]

So recently my monitor has just been randomly losing signal. Either it just goes out and I have to reboot, or it freezes up and I have to reboot. I need to know what is causing this problem because I only have enough money to replace one component. Also, I've noticed that if something hits my desk that can also cause it to blackscreen.


Here are my specs:
i5 4690k @ 4.0
Hyper 212 evo
msi z97 pc mate
2x r9 280x in crossfire
rm 850 power supply

 

[Bossyfins]

Make sure all the plugs are connected.

 

[codenameveg]

Make sure all the plugs are connected.

they are all connected, I thought that was it in the beginning but I guess not.