I bought a Lenovo Thinkpad (T430) to the flies market near were I live. Price was very low and it was in a very good condition so i bought it for my wife to replace his 6 years old X200. Lenovo computer are (almost) always incredibly strong and very well built. This one cam from a auction, cause auction number are still on the top of the computer. Only problem bios need supervision password to alow user to make modification. I verified it before bought it but not enough.
So, people on internet advises to shortcut SDA (data of I2C) and SCL (clock) of the EEPROM who contain password (or hash of the password) at the right beginning of the computer power’s up. Shortcut, probably to avoid BIOS from reading the EEPROM. But put them to the GROUND should be the same. SPOILER : It worked great ! And it should work for a lot of different model from Lenovo. By the way, Lenovo was the worst (or the best, depend of your side) computer for BIOS password cracking. Because you have to tear down and solder or connect directly thing on the main board to bypass bios. Every other computer have generic password who only need about 5 sc to be find on internet.
I found, not in this video it-self, (https://www.youtube.com/watch?v=ANZjUPUYE7s) but in the comment, this information :
You can find useful information here : http://www.ja.axxs.net/t430.htm This web site give you a lot of information about a lot of computer and especially SDA and SCL emplacement via.
You can see on picture below that I have soldered directly small wires on the main board, and connected it to a test board with one button (because i’m a lazy guy). It worked Like a charm. Some people say it was hard to find the good timing but it worked at the first time for me.
I made a timing diagram of the BIOS reading the EEPROM with my DSlogic analyzer but did not do a screenshot. Sorry.