Foxconn 2ABF and from what I cant tell has no bios.
The board will have a BIOS, it has to have a BIOS.
Appears that board came out of an HP system.
First of all, I'd look to clear the CMOS. If you cannot access the BIOS (likely F10 for an HP OEM system), then you could remove the CMOS battery for 10mins. Looks like it's located to the top-right of the motherboard.
Some (most?) BIOS have an option to disable cores. Whether you have the option on that board and exactly where you'd find it in the BIOS, I'm not sure - and it may even vary by BIOS version, but it would make sense that somehow a core has been disabled.
Clearing the CMOS or "loading optimized defaults" in the BIOS should achieve the result without having to...