Black Screen - HD 7970

[Parameign]

Computer Specs:

CPU: i5 3570K
GPU: AMD Radeon HD 7970
MOBO: Gigabyte Z77-DS3H
RAM: 8GB Corsair Vengeance DDR3
PSU: 750W Corsair CMPSU-750TXV2 80 Plus
HDD: 1TB Western Digital Caviar Black SATA-III
OS: Windows 7 Home Premium 64-bit (Service Pack 1)

Software & Peripherals:

Avast! (current) & Symantec Endpoint Antivirus (old - same problems)
Google Chrome
Guild Wars 2, Rift, Planetside 2, League of Legends (a few other installs that have since been removed)
Spotify
Skype

Razer Naga 2012
Razer Black Widow Stealth Edition
Steelseries Siberia v2

Background/General Info:

To start, I received my computer (built by CyberPower) on the 15th of December. I had black screen issues within days but I thought I had fixed them. More issues arose. Most of the problems are black screen crashes but I've also seen a couple issues where the screen turns a color (purple, for instance) and features dark, vertical lines running down its length. When the black screen occurs, I lose sound as well. This has happened primarily during my time watching video content (Twitch.tv's live-streams and Netflix) but it also occurred once during a game of Tribes: Ascend (the first time playing the game, by the way). To my recollection, none of the crashes have similar circumstances other than the existence of a video streaming service. Most of the time I'm running a few browser tabs in the background and Skype at random intervals but my attempts to replicate the issues mentioned above have failed. They seem to be completely at random so I've found it difficult to diagnose.

I have been in contact with CyberPower and, by their recommendation, I have re-seated the card (it wasn't really out of place the first time but, at that point, I was trying anything). I have also re-installed the drivers (three times - the first two failed for one reason or another) and used DriveSweeper during the re-installation process. I have also taken the time to ensure that every driver for other components of my system are up-to-date as well as software updates for programs. I've checked event logs again and again but I have found nothing related to hardware problems. The only events that occur are the one that tells me that the kernel lost power unexpectedly (Event ID 41) and the event that the previous shutdown occurred unexpectedly (Event ID 6008 Qualifier 32768). I've monitored temperatures under load (no stress tests or anything of the sort, just CPUID).

I've spent hours looking on other forums and I have found similar problems to my own but very few have defined solutions (I'm guessing there is no one solution but I have yet to entirely grasp what is going on with my computer and I would like to cover all of my bases). Through my own fiddling and browsing other forums I think it may be the video card which means that an RMA would be in order. I would like the opinion of someone else aside from the service representatives that I have spoken to (not that they are wrong or anything, they've been great, but I just want to be sure).

Thanks in advance,

Para

P.S.  I can provide anything else you would possibly need to assist me with my problems. Just let me know what I can do to help!

[Kurtiskain]

It certainly sounds like a graphics card issue. Lines and colors on the screen generally point to graphics V-Ram being bad. Does your motherboard support MVP by LucidLogix at all? it is possible the shared memory lines are being corrupted and causing these issues.

I would also have pointed to power as a culprit but I see you have a decent supply in there

I had an issue with my P8Z77-v LX similar, my old HD4870 would post and run, but at 4x only, not 16x. My new HD7870 didn't run at all, until  RMA'ed the motherboard.

Are you overclocking your computer at all?

[Parameign]

Thanks for you reply!

I had actually figured about the same as you did. I was fairly sure of it being a graphics issue so I pulled out the GPU and have been running with the onboard graphics for a few days without issue so I'm going to RMA the card (which hopefully doesn't take too long!). I did, for a little while, think that the power supply was an issue but I didn't bother with it after the onboard graphics worked without a hitch. I've been doing most (I can't play a game or two) of the stuff I did before that caused problems (mostly the video streaming but games in general are running better). For example, Netflix and Twitch.tv's streams would crash on me all the time and I've watched hours of their content over the last few days without a problem.

I was planning on doing a little overclocking down the line but these issues popped up. 

About the MVP support... I actually had to look that up because I had never heard of it before. I'm not sure if my motherboard supports it or not. I read that it comes with certain models but none of the listed ones were the model I'm using.

Once again, thanks for the reply! I wanted another opinion to consider before I went any further.