ASUS M4A77TD / Phenom II 555 unlock no boot

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Guest

Guest
Good morning,
I am new at this so I will try to be as detailled as possible.

Problem:
when I enter the bios and set the ACC to auto and then try to unclock the cores by selecting unleashed. I then exit the bios and it reboots the system as expected. The screen message for the ASUS bios loading appears (one white line of text on black screen: normal) and instead of then going to the ASUS bios screen (large ASUS logo on green background, press 4 to unclock cores, press DEL to enter bios settings...) all I get is a black dark screen. The PC runs but does not load. All I can hear is the fans running.
Nothing else happens and if I switch the PC off, the same thing happens again.

All I can do is flash the bios directly on the mobo with the jumper directly. At that point, the bios default settings are back and the PC boots as a normal 2 core CPU.

Question: why is the board doing this? Is this normal? Should I have waited longer for the cores to unlock? Does this just mean the 2 hidden cores are so unstable/broken they cannot be unlocked?

I bought this CPU because it seemed like a good deal for $100. I don't need the unlocked cores nor did I buy it for this reason. However I expected that if the cores were bad my system would just be unstable. I did not expect that it couldn't even boot up. Therefore I am wondering if this is not the CPU but the motherboard?


Details:
Bios: most recent bios was updated. I did that last week.
Overclock: none so far
ASUS M4A77TD AM3 AMD 770 ATX AMD Motherboard
AMD Phenom II X2 555 Black Edition Callisto 3.2GHz Socket AM3 80W Dual-Core Desktop Processor - C3 Revision Model HDZ555WFGMBOX
G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-4GBRL