jj44ones

Need Help With Radeon 7950. Not Displaying

12 posts in this topic

I have one Sapphire Radeon HD 7950 (11196-19-20G). It powers on and the fans run, but I cant get it to display to the monitor through DVI or TV through hdmi.  I have it running on a motherboard from 2007.

I have an older MSI video card in the motherboard that is currently working in the same pci-e slot through DVI.

 

Here's a link to the motherboard: 

http://www.newegg.com/Product/Product.aspx?Item=N82E16813131022

 

I also have the card and motherboard plugged into a 700w power supply.  But when I bought the card off of someone on craigslist it had only one power cable to hook up to the power supply, could that be the problem because I see people talking about two power cables. And I do see two power ports? 

But it does power on and fans run.  

 

Here's a link to the power supply:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817151031

 

I doubt the card is broken because the person who sold it to me offered to buy it back from me about a week ago sense he was getting back into mining.

 

Running Windows XP

 

Any help is appreciated!

Thanks

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Hi jj44ones, and welcome to the forums btw,

 

It seems that the card, HD 7950 is not receiving the power required to operate, you need to connect the 2 power cables to the graphics card in order to work as it should.

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Hi jj44ones, and welcome to the forums btw,

 

It seems that the card, HD 7950 is not receiving the power required to operate, you need to connect the 2 power cables to the graphics card in order to work as it should.

Where do I get the second power cable from? The one that I do have has 3 pins that plug into the power supply cables.

Is this a standard power cable that I can get from a computer store or is specifically made for the 7950.

Thanks!

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You need something like this: CB_033_OK_27231_350.jpg

It should be available at almost any PC hardware shop near you, it's an universal model, not only for your graphics card model.

 

PM: Please don't send me PM's about this subject, we can discuss it here ;)

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You need something like this: CB_033_OK_27231_350.jpg

It should be available at almost any PC hardware shop near you, it's an universal model, not only for your graphics card model.

 

PM: Please don't send me PM's about this subject, we can discuss it here ;)

Thanks! Will go get it now and will update. 

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Oh man I had the same motherboard few years ago. It was the worst piece of hardware I have ever bought (multiple BSODs, constant crashes).

 

I tried to find more info about your PSU, and it appears it does have all required connectors:

 

Included with the PSU are:

  • Graphics card cable with two 6-pin connectors (50+55cm; you may want to plug this cable into the PSU with the central connector and attach the other two connectors to your graphics cards)

 

 

You should have two 6-pin cables, which can be directly connected with the card. Did I miss something? You don't need molex->6pin converter.

 

http://www.xbitlabs.com/articles/cases/display/atx-psu7_15.html

 

lqUzgBl.jpg

 

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Since that PSU is modular, I though that he lost the cables or something.

You know, sometimes the most easy stuff can be really hard to solve ;)

It makes me remember the old days, before I was a graphics card aficionado...

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I'm glad my PSU comes with a bag for cables, I would never find them :P

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You need something like this: CB_033_OK_27231_350.jpg

It should be available at almost any PC hardware shop near you, it's an universal model, not only for your graphics card model.

 

PM: Please don't send me PM's about this subject, we can discuss it here ;)

 

I wouldn't recommend a molex PCIe adapter on your highend GPU. It won't supply enough power and generally you should only use them on lower powered GPUs.

 

These are the cables that come with your PSU, click to view larger image:

kHx2nNpm.jpg

 

As you can see it already comes with four 6-pin PCIe cables, plus the Sapphire comes with two molex to 6-pin power cables.

This card requires the two 6-pins power connectors, no two ways about it: "2X75 Watt 6-pin PCI Express power connector is required."

rufstf0m.jpg

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I never tested the molex PCIe cables, but I don't agree that they won't supply enough power to the GPU, each one should give 75W, resulting in 150W+75W(from PCIe bus)=225W, more than enough for that card.

As he said, only 1 power cable was supplied, not two molex to 6-pin, like it should be.

 

The strange thing is that the PSU must have the PCI power cables, but since it's modular, maybe the user didn't know where they are, likely lost them.

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So long as he doesn't overclock AT ALL and it's temporary it should do but he really needs to sort out where his two PCI Express power cables are.

 

4-pin molex PCIe cabled won't be stable (rated for UP TO 60W) but the dual molex PCI will be. When it comes down to it they aren't designed to power highend GPUs with the high currents that are for designed for running drives. Compared to a higher quality PCI Express cable that is reinforced and can withstand very high temperatures. PCI Express cables can avoid potential for the wires to burn, they are sufficiently grounded and avoid issues with the GPU which can exhibit abnormal behaviour when running off the molex PCI adapter.

 

For the sake an expensive item seek replacement PCI Express cables compatible with your PSU or buy a new one with more cable options, plus it will make your case a little neater :)

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PCIe supplies up to 150W (rated at 75W, as you all know)
6-pin/8-pin both do up to 288W (speced of 75/150 as you also know)

I'm not sure what the real power supplied by the 4-pin Molex is.

-Q

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