Rainbowy lines on one monitor

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I'm not sure how to word this so please forgive me if it comes out a little odd. I have an amd 7750. I've had it since its launch. This is the first problem that I've had with it. I have 2 monitors... just now my main monitor went black with rainbow lines all over it while the second monitor was perfectly fine. I had to reboot to fix it. What do you think's going on? Is my graphics card dying or just the dvi port?

If you need any more information just let me know.

 

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After looking into this a little deeper I've found that the memory clock doesn't go into 2D speeds. Which I underclocked a little because it was making the card run warm. Is this normal for a dual monitor setup? I think what it is, is that over time the memory gets too hot and causes this to happen. AMD control center shows the card running at 43C and it's slowly climbing as I type this. Should I underclock it further, or is there away to get it to downclock to idle speeds?

Edit: The default memory speed is 1125. I currently have it set to 1000. Which stopped the temperature from climbing... it's staying at 42C. The normal idle temp for this card is 35C.

I found a way to cause this to happen. If i play a trailer on steam on one of the monitors... it causes it to have a quick line flicker through that screen about half way down. If I keep clicking the trailer it will make the picture on that monitor scramble and I have to restart my computer to fix it.

Very weird, should I just buy a new graphics card since my 7750 is out of warranty? I'll continue to do more testing. Hopefully someone will lend me their thoughts on this issue.