AMD Phenom II X2 555 BE, core unlock suddenly not working?

[babalenong]

Hello, i have a Phenom II X2 555 BE since pretty long, around 2 - 3 years ago, ever since i have it i immediately core unlocked it with my ECS A880GM-A3 mobo, which makes it turn into a Phenom II X4 B55 , a few days ago i installed windows 7 64 bit to compensate for my 4 gigs of ram, when i start my system with its core unlocked, it will restart after the BIOS screen, but if i disable the core unlock it boots to OS just fine, so my question is

- Does 64 bit OS makes a difference in core unlocking?
- Does my 3rd and 4th core burnt out?
- Is my motherboard core unlocking function broke?

Also extra info, i tried core unlocking but keep the 3rd and 4th core disabled, and it still wont boot into OS, motherboard problems?
Sorry for bad english, i will try to give additional information if needed, thanks!
also it is worth mentioning im no computer expert, but i try to make my explanation as short as possible

 

[babalenong]

anyone...?

 

[damric]

http/www.overclock.net/t/535501/amd-k10-5-core-cache-unlocking-guide

 

[Togeltransit]

I had a similar problem as this, but the unlocking stopped not because of an OS upgrade. It's likely because I plugged a fan connector to the CPU connector from the PSU, which damaged the CPU rail; It still could unlock, but everytime I turn on the pc, I have to press the reset button twice; Booting into X4 failed, then press reset once to boot, which succeed but CPU becomes X2, when it's posting, I press the reset again, and now it runs as X4, and when it runs X4, it runs smoothly, never had any problem, even for max-load gaming.
The solution was apparently just replacing my PSU with a better/stronger one (on the 12V rail). It's Seasonic X650, and now it boots as X4 without any problem at all, always.