All how tos and vids told me to flash  silent bios with custom rom not the oc bios.

All cards flashed with https://anorak.tech/c/downloads/sapphire   custom powersave bios.

Any device in windows device manager?
Do you see your card in ATIFlash if it's connected to your mainboard without riser?
Is any of your cards able to boot up and mine with default oc bios?