[SOLVED] Monitor Glitching/Flickering every few seconds.

[smashmouth900]

Warning: Following video contains flashing lights.
So this is my older brother's old monitor, it did this on his computer, my laptop and my xbox one. It's a Benq GL2250, 1080p 60hz LED monitor. VGA doesn't work (not a big deal), not sure about DVI, and this is on HDMI.
It works fine for 10-20 minutes, then this starts. Nothing wrong with any of the cables, as I tried it with different ones.
Any suggestions?
Video of the glitchy.

 

[smashmouth900]

don't worry, i just opened it up and disconnect and reconnect all the cables and it worked. perhaps just a loose connection.