My steps to my problem. Really hoping someone can shed some light, for a possible quick fix. :(
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I first removed my old 460 card (still working)
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I inserted the 660GTX
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I installed the latest drivers [347.25]
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Simple tasks work fine. Browsing, watching 1080p rips etc...
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Launched Call of Duty 4: Modern Warfare Multiplayer: Works fine, until the map loading completes. I chose my weapon and started sprinting and the display goes blank. Not for a few seconds, but forever, until reboot. The fan on the tower still circulates. the keyboard lights are on but unresponsive.
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The system would make a quick *tsp* or *hiss* sound, as the screen goes black..
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Rebooted
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Launched FIFA15, screen goes blank even before a match begins.
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Hard shutdown
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Unplugged the DVD drive, just in case it was a power issue with a simple fix.
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Reinstalled GPU drivers.
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Ran FurMark. The 720p and 1080p tests ran flawlessly. GPU temps went up to 70-71 Celsius at max. test ran for a few minutes without an issue.
At this point, I was thinking thinking "hey maybe, problem solved".
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Smile inserted to face " :) "
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Relaunched Call Of Duty 4: Modern Warfare
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Display goes permanently blank again, until reboot. [No signal] on TV.
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Here is a list of some of the parts
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Coolmax ATX 600W 120mm Silent Fan Semi-Modular Power Supply CU-600B
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BIOSTAR AM3/AM2+/AM2 DDR2 AMD 785G Micro ATX AMD Motherboard TA785GE 128M
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AMD Phenom II X4 955 HDZ955FBGIBOX 3.2 GHz/6 MB L3/125W Processor
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4 GIGS of ram
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Windows 8 pro

Sajin
It's probably your PSU. You could try doing the following things I listed  to see if it helps resolve your issue.

Thank You. I appreciate the reply. I don't think I am even going to bother with the fan part, as the temps are ok. I had a feeling it was the PSU, as its around 4 years old and the system would make a *hiss* or *tsp* sound, as the screen goes black. I already sourced a PSU that i'll order soon. Let me know what you think.
 
>> amazon.com/gp/product/B008RJZQSW/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER <<
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ill be sure to update this post, when I receive the new PSU.

Sajin
PSU would be better than the CX750.

I see that you recommended me to a PSU that's lower in the overall advertised Watts. So I'm guessing that the overall W isn't everything?
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Why that one, over the one I chose?

Sajin
Read the following articles and you'll see why...
 

 

Hey bro, So I ordered the Seasonic PSU, a few minutes ago. So I should get it in a few days. Can you suggest an affordable AMD chip, motherboard (ddr3) for an ANTEC 300 tower? I am still running ddr2 (upgrading part by part) and I am searching high and low for 2, 4 gig sticks of ram because 2 of my slots are bad (out of four), but they are expensive. So I think that's a sign that's telling me to switch over to ddr3. Although, I don't really see any difference with simple tasks.
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The main reason I haven't switched over to ddr3 yet was because I am using an h60 Antec CPU cooling system, that's connected to my cpu, so swapping is out will be a task. But i think i'll have to go through with it.
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My current CPU is an AMD Phenom II 955, so I'd prefer that the new board can support that, because I don't plan on upgrading that CPU just yet.