I have just received an old Inspiron 570 and i am attempting to install my old GeForce 8600 GT on the board. The fans spin up to 100% on boot up and do not wind down and give a black screen when run through the card. Bios nor windows recognizes the card is there. I have tested this card to make sure it works in my other rig where it works fine. I have also tested a Radeon HD 4650 in the Inspiron and that boots just fine. The only thing that i can think of now is that the board is a PCIe 1.0 and the card is not fully backwards compatible.
mobo - MA785R Dell OEM model # - 04GJJT onboard Video - Radeon 4200 4 gig DDR3 Athlon II x2 240 PSU - 300W
EVGA E-GeForce 8600GT 256 MB
More aboutvideo geforce 8600
I'm pretty sure the gt8600 is PCIe 1.0 card. I think the power supply isnt adequate for this card, and thats why it wont run for you. The 4650 requires less power
I don't believe it to be the power supply. I just popped in an Orion 450W supply from my other computer into the Inspiron and still received a black screen and 100% fan speeds.