Black screen after installing new power supply and pci express graphics card

[Bunit1]

 

So i installed a new evga 600w 80plus certified psu and installed an xfx hd 6950 pci express x16 video card in my hp p6754y computer.  Hooked it up to my tv with an hdmi and turned everything on, but I just get “no signal” on my tv...its not connecting. I was told that since my pc has a legacy bios, that i could not install a graphics card newer than a amd radeon hd 6xxx model...so i went with the 6950, assuming it would work.   And i was told that once the pci express card was installed, it would automatically stop using the integrated graphics and use the 6950 without having to do anything.   Anyone have any advice?! Keep in mind that I dont know jack about computers lol.  Also...the new psu has 2- 6+2 pin connectors but the graphics card only has 2- 6 pin connector slots(in the picture).  Would that be the correct way to hook it up...just using the 2- 6 pin connectors from the psu and leaving the 2-2 pin connectors off??  Thanks!

[Paul_Tikkanen]

Hi:

The only question I would ask is:  Did you install the supplemental 6 pin power supply connectors to the card?

According to the general specs for the HD 6950, that card needs to have two of those 6-pin supplemental power supply connectors attached to it.

AMD Radeon HD 6950 Specs | TechPowerUp GPU Database

If you did, then I wouldn't know why the card isn't working.

[Bunit1]

Yes. In the picture I posted you can see the two 6 pin connectors from the power supply going into the two 6 pin connectors on the graphics card...and i left the two 2 pin connectors unconnected...i think thats how it would be connected, right??

[Bunit1]

Im using an hdmi to connect the computer(using the new graphics card) to my tv...i would think that would be fine...maybe i have to use the dvi slot on the graphics card? Maybe get a dvi to hdmi cord and try that?

[Paul_Tikkanen]

Yes, it appears you have the card installed correctly.

The HDMI should have worked.

I doubt that a DVI to HDMI card would make any difference, but that is just a guess.

Did you test the onboard video connection and see if you get a display.

That would be to test to make sure your video card disabled the onboard video.

It should have.

The only other thing would be...is 200W too much for the PCIe x16 slot to handle?

All of my PC's have PCIe x 16 slots that are only rated up to 75W, and your PC's specs don't provide detailed info like that.

I have AMD Radeon HD 6570's in two of my HP PC's that have legacy BIOS', and they work fine.

I used the original 320W and 365W power supplies they respectively came with.

The HD 6570 draws 60W of power.

[Bunit1]

Ya i took the 6950 out of the pc and the computer is working just fine now(with a vga wire).  I installed a new power supply...a 600 watt, so id think thats more than enough to handle to 6950 and whatever else i throw at it. How would I test the onboard video connection?

[Bunit1]

 

 

Would i have to go to the device manager and find the onboard gpu and disable device, then shut off pc and install the 6950, then restart the computer?  It should automatically shut off the inboard gpu(ati radeon hd4200) automatically though, correct?

[Paul_Tikkanen · Accepted solution]

I would install the Radeon graphics card but leave the monitor cable connected to the onboard video.

If you don't get a video signal from the onboard graphics after you install the video card, then the PC knows there is a graphics card installed and disabled the onboard video.

If you do get a signal from the onboard graphics adapter, then the PC for some reason doesn't even know that the graphics card is there.

[Bunit1]

Ok. Ill try that and see what happens