XFX 7870 DD No Display

[Junpaku]

The GPU I had installed on my PC is GT 210. I uninstall the nvidia drivers and rebooted it. Then, I turned off the computer, installed the 7870 onto the mobo and connected one 6 pin to it (my current PSU has only one 6 pin, 7870 has two 6 pin slots). When I start up I get no signal on monitor, cannot see BIOS as well. Next I remove the 7870 and start up with onboard so I can get into BIOS and disable onboard graphics and enable PCI. Then I reinstall the 7870 and connect the 6 pin and then start it up, still no signal. I reinstall Win 7, repeated steps above and still wont work.
I have tried using Driver Sweeper in safe mode to remove any traces of Nvidia drivers.

Notes: I am using a DVI to VGA Adapter since my monitor only has VGA. The fans on the 7870 do spin. When I disable onboard and enable PCI while using GT 210 I get signal.

Specs:
CPU: i3-3220 3.30 GHz
Mobo: GAB75M
PSU: CM 500 watts
1st GPU: GT 210

Any help is appreciated.

 

[DominionSeraph]

Connect the other 6 pin.
Didn't the card come with molex to 6 pin?

 

[Junpaku]

Unfortunately the card did not come with molex to 6 pin. My current PSU only has one 6 pin. Would that be the problem? Isn't one 6 pin enough to at least start up the GPU?
I have also tried the DVI/VGA adapter on my 210 and it works. Tried on a different monitor and still black screen. Windows does log on (I can hear start up sounds), but no display.

 

[dave_the_nerd]

Yes, it's probably the power cable, or lack thereof.

I have a 7750 which never pulls more than 50w (max PCI slot power is 65w) and it still won't fire up without the 6-pin plugged in.

I think newer cards have some kind of failsafe. If they aren't getting voltage where they expect it, they won't even try. (I had an older card that would crash without power if you tried anything 3D, but at least it would POST and show a VGA BIOS message.)

 

[DominionSeraph]

I have a 7750 which never pulls more than 50w (max PCI slot power is 65w) and it still won't fire up without the 6-pin plugged in.

What 7750 has a 6 pin?

 

[Junpaku]

Thanks again. Got the molex to 6 pin. Works like a charm!
Really appreciate it.

 

[dave_the_nerd]

What 7750 has a 6 pin?

The fancy overpriced OC edition from XFX. It has dual DVI.

 

[Face2Face]

I have a 7750 which never pulls more than 50w (max PCI slot power is 65w) and it still won't fire up without the 6-pin plugged in.

Max is 75Watt