Graphics card changing

[computerinneed]

I have had and issue with my graphics card where it was fine up until recently. I have an Nvidia Ge-force 8600 PCI-e card. I turned on my computer one day and the monitor didn't come on. I put the cord into the onboard controller and it worked. I haven't changed any settings. I have no idea why it switched back. I need help determining if the card is dying or something. now is seems to be going between them. Twice now it has switched back and forth please help.

 

[scout_03]

disable on board in bios and see if 8600 work,or have a friend to check the 8600 in is computer.