Continued issue using unlocked 6950

[zombiegenesis]

A few days ago I came here with the purpose of understanding a problem when my PC booted. I was since able to identify that the problem only exists when using the BIOS setting of the unlocked 6950 (not using 6970 BIOS).

Essentially, I start up the system and the lights come on, but nothing boots. And then the noise of a moderately sized plane engine comes from my rig until I have to shut it off manually.

Can anyone identify a reason for this? I'm still stumped. On standard BIOS everything runs just fine.

 

[zombiegenesis]

Should also note I HAVE run the BIOS version before without this problem. For about a month actually it worked just fine.
Only recently has this been happening.

 

[Meaker]

The jet plane is all the fans going into default high since the cards are not initialised properly.

 

[Ezyryder]

Have you tried uninstalling the card, taking it out and then putting it back in?

Uninstall the drivers as well and then install them again...

Which unlocked bios are you using btw?

 

[tommybhoy]

Check the pcie power cables are securely plugged into the card, and if you have a modular psu, check the cables not came loose from that end either.