Samsung does not host BIOS downloads on Samsung.com for old motherboards anymore. However, you can still find official updates:
Are you looking to like overclocking or PCIe speeds, or do you just need to fix a boot issue ? Samsung B75s1 Bios
If F2 doesn’t work, try:
Users often seek to modify this BIOS to overcome OEM-imposed limitations, such as a 16GB RAM limit Samsung does not host BIOS downloads on Samsung
To enter the BIOS configuration on most Samsung systems, users should restart the device and repeatedly tap the key during the initial startup logo. Advanced Modding & Limitations: Samsung B75s1 Bios
The B75s1 BIOS is "locked" to prevent user interference that could destabilize the AIO form factor.
