I don't think nothing happened while swapping the GFX cards, Windows works OK. When I say that even with the USB install doesn't boot, is because it does exactly the same than when booting from the EFI partition, Chameleon starts to load but don't finish booting (with the USB it doesn't display the alphanumeric error, it just doesn't continue).
I am nearly sure that if I put my old card again it should boot. I know that these 280x cards have a bigger bios than normal cards, maybe this is the problem with chameleon.
I appreciate all your help
EDIT: Solved! I replaced chameleon with Clover and it works perfect.