Inspiron 580 external display problem

[bossox]

i had inspiron 580 and i wanna change graphic card to my old hd 5670 and the power supply pure 400 watt

i have installed this card on my pci, already updated the latest bios but it still cant detect my 5670.

the screen just goes blank when i start the pc. but it's already connected when i disable internal video adapter from device manager

and the other problems come in,

when i restart/shutdown the computer, it's begin like that again, can't detect my 5670 and screen goes blank or usually got beep (i never count it)

i must connect to internal adapter first disable it, pull out the electric source and move to external adapter. it works but it so rare

so i must retry that step everytime when turn on my inspiron 580.

i just tired to do that , can anyone help me for this problem ?

 

[clutchc]

When you connect to the integrated video and enter BIOS, do you select the PCIe slot for default instead of the integrated?

 

[bossox]

my bios doesn't has any feature to change which primary video adapter in use

 

[clutchc]

Dell made the Inspiron for many years. With many different generation processors and motherboards. Is this the model you have, or do you have one of the older models?
http://support.dell.com/support/edocs/systems/insp580/en/cs/cs_en.pdf

My original post was assuming you had one of the older 775 socketed C2D or C2Q systems.