Video is occasionally crashing to black screen (monitor loses connectivity and goes blank). PC is still running like normal while it happens (it is not powering off). A hard reset fixes the issue until it happens again.
This problem has been happening for the last 2 months intermittently and I am having a heck of a time diagnosing what is causing it.

I have tried:
1)Video driver uninstall, re-install (With DDU in safe mode)
2)Video driver uninstall, re-install with beta drivers (With DDU in safe mode)
3)Switching around my power supply modular connectors to different parts of the rail(s) (no difference)
4)Switching HDMI 1 or 2 connector on monitor (no difference)
5)Bios Update, video card firmware update (no difference)
6)Reverted back to stock clocking (no difference) Only CPU, GPU has never been overclocked as it was fast as hell.
6)Changed PCiX position on the motherboard (at this time, has not black screened yet...been almost a day)

The problem does not always happen within a few hours. Sometimes it will work fine for 3-5 days with no issues, then one day it will black screen every 15 minutes like it is its job, requiring a hard restart every time. Troubleshooting has been a nightmare. The problem almost always happens while simply reading an article or cruising youtube, it has never locked up while gaming (Metro Redux, Battlefield 4, etc at the moment).

-The last thing I have changed with my system-
The machine has run fine for 2 years with 0 issues. I installed a new Asus 290X DirectCU II 4GB in March/April of 14.
It ran fine up until recently and problems only started happening in August of 14.
I contacted Corsair thinking it was a PSU problem but they are directing me more towards a GPU or MOBO issue.
They offered me and RMA but I am trying to diagnose whether or not its the culprit
Asus tech support told me to try an RMA on the video card and we started a case #NA4103051

Does anyone have any advice on what I can do to figure out what exactly is screwing up and making my machine black screen? I have been building computers since 1999 and have never ran across an issue like this before.
I do not want to start RMAing stuff that might be OK.

Any ideas?

Specs:

Motherboard Asus Crosshair V Formula-Z
Processor AMD FX-8350@4.82ghz
Memory OCZ AMD Black Edition 8GB (OCZ3BE1600C8LV4GK)
Video Card ASUS Radeon R9 290X DirectCU II 4GB
Hard Drive # 1 Samsung 840 PRO SSD 256GB
Hard Drive # 2 Western Digital Caviar Black 1TB
Optical Drive # 1 LiteOn iHBS212
Power Supply Corsair 1000HX
Case Corsair Graphite 600T
Sound Card Asus Xonar DX
Monitor LG W2486 24" LED LCD
Operating System Windows 7 Professional x64 SP1