Monitor often times will not wake up, but KB/Mouse PC seem alive

Windows 8.1
Sapphire R9 280X stock currently

About 1 in 5 times I sit down at my PC, my monitor will not turn back on when I jiggle the mouse or press keys on the keyboard. I have to hard power off the machine by holding the power button, then bring it back online. No other way to recover. I dont sleep my computer, simply turn off the display after 15 minutes. I have been battling this for weeks and enough is enough, I need to fix it.

Thing is ... I'm stumped. Looking for any kind of advice, low or high .. bring it on [H].

Try a different input and or different cable if you havent already.

Hmm I haven' thought of that, I'll give it a go.