I have this board along with Ph II 720 & using the old bios 78DEA113 BS
They said this is the correct bios 4 unlock,
But it wont unlocked, when ACC is turned auto, the 4th core is detected on BIOS but thats it...no go further than windows loading, after several seconds my pc will be immediately shutted down.
My question is:
I found this mod bios in here http://www.lejabeach.com/Biostar/TA790GX/78DBA114.zip
is there still any good possibilities that my 720 will be unlocked with this bios?
or I shouldn't bother trying?
If the fourth core is detected by the bios then it means you've successfully unlocked the 4th core. The reason it won't boot into windows is most likely because the core is defective, and changing to a different bios won't help you. Just remember that even though you may be able to unlock the 4th core there is no guarantee that it will be usable!
You could try lowering the multiplier or changing the voltage to see if you can get it to run stably, and there are plenty of tutorials on the net for that. But remember that in doing so you run the risk of damaging your processor. I wouldn't recommend it unless you have some experience with overclocking.
There should be two choices after enabling ACC, normal and hybrid, you (must?) select hybrid, to be fair I don't have a biostar but it seems to me a similar wording should be used.
Also as I recall their was a slight hesitation on the first boot as windows was looking for a new driver for the cpu, but it came up.