Hi all, I have a EVGA 9800 GTX+. This card works when I put it in my MSI motherboards (Tested in 2 motherboards)
However, in my Dell Vostro 230 motherboard when I plug the card in to the PCI-E slot and boot the computer up all the fans spin and everything however I get no signal and the numlock key does not light up (the other locks for my computer will not respond if pressed)
Now the weird thing is this - The Vostro is rocking a 500 w PSU with 24 amps on the 17v.
When I put my GTX 650 TI in the Vostro or an Integrated Card it boots fine.
The 9800 GTX+ boots fine on a MSI mobo with an i7-3770k and another msi motherboard with an amd phenom 980.
Make sure drivers higher than 178.14 does support the 9800gtx+, as for the GPU not running in your Dell, it could be that it's BIOS might be older than the GPU and thus it doesn't support it (I've no idea how recent that vostro is).
The only thing I can come up with is that the PC with the Vostro mobo is using more power than the other builds, given that your PSU only has 24A@12V+ its likely that there's not enough amperage to run the 9800GTX+