AMD Unlock question

[Dr soggy]

Hello,

I tried to unlock a Phenom x2 555 today and had limited success. It registers in BIOS that it is a quad and can get to the Windows 7 startup logo, but no further. Does this mean it's a bad core/cores or a voltage thing? Thanks in advance.

 

[Dr soggy]

Do you think updating the firmware would help in my situation? Also I was going to try to manually turn off the fourth core. In my bios I have the option of turning 2-6 cores off. Does this mean to have a tri core I would turn off cores 4-6?