2x Radeon 4870 Problems

[Liamrt]

Hey all.

I recently bought 2x Radeon 4870 512mb with crossfire. They are both hooked up as they should be, lights on fans spinning. However, only one appears in both device manager and Catalyst Control Center.

I was wandering, is this some sort of BIOS setting problem, or is one of the cards dead?

Thanks for your help.

 

[JN]

Have you tried each one individually to narrow down which one may be the problem?

 

[Liamrt]

Just tried starting up, first time with the power to the first card taken out, I got a flashing red error telling me it was disconnected. Did the same with the second card, no error.

So I'm assuming it's the second card. Im also guessing that because the first one gave an error and the second didnt that perhaps it is the BIOS not picking up the second card?

 

[monkey7]

Just a stupid question and it will probably hurt your pride, but did you connect the 4pin molex which is required for crossfire to the motherboard?

 

[Liamrt]

To be 100% sure i just took my cards out, switched them around, still works fine, so I guess that means atleast both cards are alive.

Checked everything connected, card into slot, both PCI cables into each, and 2 crossfire connectors over the top. Should there be anything else connected to the cards? Wouldn't suprise me if I'm being a complete idiot.

Mini update. I was getting 3 red lights on my second card. So I took it all apart again, re assembled and now the lights have gone, I'm just hoping they havent gone because it's totally fried - but i have no way to find out seeing as my pc never acknowledged the second card anyway.

 

[Liamrt]

I have no idea how I managed it, but uninstalled every driver I had, took it all apart again, switched it all around again and it worked! Not sure how but woo. Thanks for your help guys.

 

[°TheMadDutchDude°]

Didn't you uninstall your old drivers?

I have heard from other sources that some times you have to install each card on their own in the top PCIe slot (strange I know) to get them to work, some times that helps with SLi too. This requires putting one in, booting up and installing, turning off, then taking it out and slotting in the other one, booting up and installing the drivers for that one, it seemed to sort a problem out but I am not sure if it is the same in every instance!

 

[Liamrt]

That's probably what I ended up doing actually, I switched them around enough times so that could be it. Strange.