Chimera stops working after hardware change

[mrbrdo]

My system:
- OS X Mountain Lion
- normal BIOS (not EFI)
- Fusion drive (I think this could be significant for the issue) - 1xSSD 60GB and 1xHDD 1TB
- dual boot with Windows 7

Changes made:
- replace Nvidia GPU with AMD Radeon R9 280X
- plug SATA cables into different sockets on the motherboard (because the new GPU is blocking the ones I used before)

Problem:
- when booting from the drive that should present me with Chimera choosing screen, I will get to "boot0: done" and after that it will display a few unreadable characters, and then hang (nothing happens)
- I can boot from the other disk but that one boots me straight into Windows (it worked like this before too), Windows works fine

I tried booting Chameleon via USB following this guide: http://tonymacx86.blogspot.com/2009/11/create-chameleon-boot-usb-drive.html
It also hangs with "boot0: done" (and blinking underscore) BUT there are no unreadable characters displayed after that, those that I get when I boot from my disk.

 

[mrbrdo]

Ok to answer my question, Chimera doesn't seem to work well with the new AMD cards, you need to set integrated graphics as first enabled device in BIOS settings... Then Chimera will work but on the integrated graphics display connector.
However my card will not work with Chimera (blank screen after apple logo), but it will work with Clover just fine. However I cannot seem to get rid of Chimera, I install Clover but when I reboot it's still Chimera that shows up.