Video card not being detected by monitor after switch

[Rysol]

after purchasing 2 new xfx radeon hd 6970, to run in crossfire, for optimal gaming, my monitor wont detect the two cards. I have tried placing the old card back in and it responds just fine to that one. With the new cards in, everything sounds like it boots and all the indicator leds on my motherboard show up just fine.

this is the exact video card im trying to use:

XFX HD-697A-CNDC Radeon HD 6970 2GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card with Eyefinity

this is what im running besides the xfx:

AMD Phenom II X6 1090T Black Edition (125W) Six Core Socket AM3, 3.2GHz, 9Mb Cache, 2000MHz HT, 45nm

Asus M4A89TD PRO/USB3 Socket AM3 AMD 890FX + SB850 Chipset DDR3 2000(O.C.)/1600/1333/1066Mhz 2x PCI-Express 2.0 x16 8-Channel HD Audio GigaLAN 2x USB3.0+12x USB2.0 6x SATA 6Gb/s ATX

Cooler Master Silent Pro M850 Modular 850W Power Supply

Corsair XMS3 Classic 8GB (2x4GB) DDR3 2000MHz CL9 DIMMs, Optimized for Core i7, i5 and Core 2 / AMD Phenom II times 2

Hitachi Deskstar 7K3000 2TB 3.5" SATA3 6Gb/s 7200rpm 64MB Cache OEM

LG GH24LS70 Black SATA Lightscribe DVD-Writer 24xDVD+R/-R 8xDVD+RW/6xDVD-RW 16xDVD+R DL 12xDVD-R DL 48x CD-R 32xCD-RW OEM

Scythe NINJA 3 8 Heat Pipes CPU Cooler for Intel Socket 775/1366/1156 & AMD Socket AM2/AM2+/AM3

 

[DKRON]

take out one of the graphics cards and see if it works, your monitor only needs to detect the one card that it is plugged into so its not a crossfire problem

 

[Rysol]

yea my first problem is getting the graphics cards to respond in the first place

 

[DKRON]

so you have tried only working one of the cards?

 

[Rysol]

yep, still nothing

 

[DKRON]

and you have run all the drivers from the cd which came with the card?

 

[Rysol]

all of them, even the device manager wouldn't recognize the cards either

 

[DKRON]

hmm that is very weird, open your case and when you turn it on see if the cards power up (fan starts spinning)

 

[Rysol]

yep, and the leds on the mother board light up as well indicating that they are on and responding

 

[DKRON]

the motherboard LED's don't really tell you anything about the graphics, there must be a power shortage going to the card/s they use 2x 6 pins yea?

 

[Rysol]

yea they do

 

[DKRON]

just looked up the spec for them and some bad news, 1 uses a minimum 650w PSU which means your 850w will be on the limit to power both cards

 

[Rysol]

think my power supply isnt putting out enough power?

 

[DKRON]

it could explain everything if its not handling the cards it won't fully power either card, it does mention on the coolermaster website that its not crossfire ready but does say SLI ready so they should work the same way anyway, would try different configurations like putting one card in the second PCIe 8x slot and different 6pin powers

 

[agissi]

I'd try testing the cards in another computer with adequate power that way you can make sure they work at all. I would suspect its your PSU, but the cards could have been damaged by the low power, however I'd suspect they are OK.

 

[Rysol]

it turns out that the video card requires both an 8pin and 6pin power cable not just one

 

[DKRON]

thats why i asked you if it used 2 6pins, good to see it works now atleast