ga-ma770-ud3 rev 2.0 and 960t core unlock

Hi guys,

I've just updated from an x2 6000 to a phenom ii 960t black edition and trying to test the latent spare cores. Every forum post and even the motherboard manual I see mentions ACC, which I'm sure I had as an option before) but the latest bios (which I needed as it supported the 960t) only had the option cpu unlock. If I enable CPU unlock then save and exit the bios then the computer switches off (as I understand it should), switches back on and then no display (cpu fan stays on loud indicating no boot). If I turn off then the pc boots as normal but the cpu name does not change.

I've used CRTL+F1 to enable the advanced options but just wondered was I missing something as there wasn't an updated manual for the new bios that I'm aware of.

Specs:

GA-MA-770-UD3 Rev2.0 Bios FKD
Phenom II 960T with arctic cooling freezer 64 pro
4x1gb crucial xms 2 800 mhz (4-4-4-12, 2.1v but currently running at default 5-5-5-18 as new cpu made them unstable at 4-4-4-12)
Thermaltake Toughpower XT 675w Semi Modular PSU
Leadtek Factory OC 7600GT (Gigabyte 8800gt gpu fan has died and rma team aren't interested)
1x WD 500gb
1x Samsung 500gb
1x LG Super Multi Writer
2x120 mm case fans and side mounted 80mm low profile
Coolermaster Elite 330 Case

Sorry if I'm repeating, I searched for my motherboard model and the processor and had no luck on either.

Cheers,

Joel