While some generic guides suggest removing the CMOS battery to reset BIOS, this only clears the date, time, and basic settings—it will not clear the Supervisor Password on a T470. Verified Advanced (Unofficial) Methods
The only officially supported resolution is to have a Lenovo authorized service provider replace the entire system board (motherboard) .
Verified to work on T470 BIOS versions up to 1.25. Later versions (1.30+) sometimes patch this glitch, requiring Method #2.
You will find forums claiming that typing "1234" or "lenovo" works. However, Lenovo does provide a Service Override for Power-on Password (not Supervisor).
Before attempting a reset, identify which password you are dealing with:
If shorting fails (or you have BIOS v1.30+), you need to reprogram the SPI flash chip. This works 100% of the time because it directly rewrites the protected region.
Below is the verified reality of how to handle a BIOS lockout on this specific model. ⚠️ The Reality Check: Security vs. Convenience