I dont have very much hardware information. Just I read somethings about unlocking in somewhere. Such as, if it has 10 memory, it can be unlocked. So I am not sure exactly.
I tried below.
1. download bios gtx470 and boot system.
2. nvflash --eraseeeprom
3. nvflash -4 -5 -6 gtx470.rom
4. restart computer
While I was doing these, I didnt meet any problem.