second GPU now system wont boot

[unwashed potato!]

previous thead i've got to give some context.
http://forums.overclockers.co.uk/showthread.php?t=18314291

figured i'd get a better response with a new related thread.

this is the gpu i already had...
https://www.overclockers.co.uk/showproduct.php?prodid=GX-123-HT


this is the gpu i've just bought
http://www.overclockers.co.uk/showproduct.php?prodid=GX-140-GW

this is my motherboard
http://www.asus.com/Motherboards/AMD_Socket_939/A8RMVP/#specifications

and the psu i have is a Corsair CX 400W ATX Power Supply bought from ocuk which they no longer sell. i was wrong thought i had 450w but actually 400w

anyone any ideas why it might not be working? i've tried just one of the cards at a time it woks fine, but as soon as second is in it wont boot up and i've tried with them in both positions. also unplugged cd drive plus as much other things as possible so power usage is minimal and still nothing.

 

[Ginger-Menace]

you do know that those 2 card wont work in sli/crossfire... unless you have using one for gfx and the other for phyx. sounds like the psu isnt powerful enough, you might have to go in to bios with only the ati card attached and enable the seconds pci-e slot

 

[unwashed potato!]

i've been into bios and only setting i can see that's realted is currently set to auto any way. i'm hoping to use the second to allow a third monitor which i've recently bought. from the thread i linked in the first post it was advised to try another gpu

 

[Cool Breeze]

Your PSU is not man enough 500w or higher would be recommended

 

[unwashed potato!]

pants!

what PSU will i be looking for other then 500W+. is this almost def the issue? so i can go to members market and look for second hand one hopefully?

 

[Surveyor]

Sorry this isn't working out for you.

Saying it's the PSU is only guessing.

The 2 cards are <75W each so a decent 450W PSU should work.

It could be compatibility issues with the motherboard.

If you're not careful you'll end up with a PSU you don't want and a GPU you can't use.

I'd advise you again to return the new card under the Distance Selling Regulations.

That way all you're out is a couple of quid for postage.

 

[unwashed potato!]

i will try that i think then but what would you then suggest i try to get the 3 monitors working?

 

[Surveyor]

i will try that i think then but what would you then suggest i try to get the 3 monitors working?

The most straightforward option is to save up and get a single ATI card which will run 3 monitors.

 

[unwashed potato!]

bit of a bump but any advice as to what single ATI card will allow 3 monitors? doesn't need to be all singing and dancing as the machine wont be used for games, just want to be able to use my third monitor that is just sitting collecting dust