Multiple displays on Compaq Evo 510 ssf

[neboallen]

Hi,
I'm trying to install additional graphics cards to five Compaq Evo 510 SSF machines at work so that each can support three monitors.
I installed a PCI Radeon 9000 to do this, but when I booted it up, it didn't even make it to the POST. It gave a long beep, then two short ones; the display adapter error code.
I've tried the same card, both an AGP and PCI version, on different machines with successful results. On these Evo machines, they don't work at all.
It's not an IRQ conflict, and it's not a faulty card.
Any advice?

I've got a feeling it's to do with power, but I'm curious to see what you guys think.

 

[NosBoost300]

might have to change display settings through the bios first

i've always had a hard time changing from onboard to display adapters... pain in the arse

 

[donmccon]

Were you ever able to add the multi displays to the EVO510 SFF?