From what we know the BIOS password is reset by the maker. This is done to thwart laptop thefts.
https://forums.lenovo.com/t5/ThinkPad-T61-and-prior-T-series/T61-lock-symbol-in-the-top-left-corner-No-access-of-anything/td-p/716885 repeats that no one seems to help outside of paying Lenovo for the password reset. Yes you could put in a new motherboard but so far that costs more than paying Lenovo for the password reset.
I have a lock icon in left hand corner of my Lenovo thinkpad t410s and I don't know password and cant seem to get tech support because this old computer is out of warranty! The computer was given to me and I need it for school. Help!