Why won't it work?

[seumasbeathan]

So a few weeks ago I bought a used 5870 from someone here on the forums, I put it in my computer but it did not work, I then tried it in my brothers computer and It worked fine, I put this down to the psu, I have a 10 year old 500w psu he has a couple of years old 550w psu. So I spent another £50 getting a cx600 only to find that when it arrived the graphics card still displayed no picture, I then re tried it in my brothers pc and it still worked fine. I then tried his 5850 in mine and it worked fine.

And idea whats going on?

 

[hmmblah]

Are you running the same motherboards? What motherboard do you have? Running the latest BIOS?

 

[seumasbeathan]

He has a Gigabyte socket 775 motherboard ( not sure of model no ) I have An Asrock H61M-VS with the latest 2.40 bios update

 

[jamesriley94]

I take it you've fully removed drivers and everything from your 5850? Shouldnt make too much difference, but possible

 

[seumasbeathan]

I had just installed a fresh copy of windows a few days ago so there was np drivers installed at all

 

[jamesriley94]

Assuming the problem isnt a graphics card issue as it's worked in - I'm guessing 2 (bro's and the guy you bought it from) computers and not yours, I probably guess something with the motherboard. I have no idea what, nor why it would run the 5850 and not the 5870 though. Could try and flash the BIOS of the 5870 down to a 5850 as you're running them in crossfire anyway arent you?

 

[seumasbeathan]

Not running them in crossfire until I get a new motherboard, my current one only has one Pcie express 16 slot

 

[seumasbeathan]

Well it looks like it's an issue with my motherboard which totally sucks, Most likely Im gonna sell the 5850 and buy a new motherboard

 

[jamesriley94]

Arent you planning on upgrading soon anyway? Can you not just hold off until then?

 

[seumasbeathan]

I guess, I just still can't get my head around why a motherboard would take a 5850 but not a 5870 :L Or maybe it isn't that :L

 

[jamesriley94]

Downgrading the BIOS of the 5870 to a 5850 should show whether it is a motherboard problem though. Worth seeing anyway - can always put it back to the other one after

 

[seumasbeathan]

Ok how would I go about doing that? I have never done that before

 

[jamesriley94]

Lol, I havent either, no idea how to either.

Just know it's possible as people used to flash 5850s with 5870 BIOS as some of the shaders and cores were disabled in the BIOS and not physically removed. There should be enough guides online of how to do it

 

[seumasbeathan]

I will try some more things ( not sure what :L ) and then if nothing works I will try flashing it

 

[seumasbeathan]

Is it the 8/4 pin socket that provides power to the pci slots?

 

[jamesriley94]

No, that's CPU power. PCI slots get their power from the 24pin

 

[seumasbeathan]

Oh :/ I was gonna say that he has an 8 pin and I only have a 4 pin socket so maybe that could be it but If it's not then I'm back to not having an effing clue

 

[jamesriley94]

Nah, CPUs can run off 4 pins, just the extra 4 enhances stability during overclocks.

I have no idea why either. I could be a fault with the board with the PCIE slots not being able to provide enough power as you say, regardless of the 4 pin. That could just be a design flaw of the motherboard.

Flashing the BIOS wouldnt really show what the fault is, but it may make it work I suppose.

 

[seumasbeathan]

Just thought I would add that its not jut that the picture isnt displayed, The graphics card isnt detected at all , so Like when i use on board on video and go into device manager the graphics card isnt there

 

[Josh Weston]

Have you tried flashing your mobo?