So...upgrading an old but critical family laptop today. Cloned and swapped out the hard drive for an SSD. Swapped out for some faster and larger SODIMMs. All looking good.
OK - last thing. Check for BIOS updates. Booted to BIOS and it wanted a password.
Hmmm...looks for a solution..."take out the CMOS battery and let the BIOS reset". OK. Done.
Reads another site ...** whatever you do don't remove CMOS battery! **. Argh! Puts it back....fires up latop. No boot. BIOS errors. Windows tries and fails to load. Dead Laptop. Still wants password.
Eventually finds this article:
https://davidzou.com/articles/bios-password-bypassFinds this disassembly video:
https://www.youtube.com/watch?v=H_WbQFvlCDsSearches internet to find location of EEPROM chip for this model. Fails.
Dismantles the entire laptop down to mobo and uses a USB microscope to try and find a L08 EEPROM chip. Looks at every likely candicate on the board.
Finds it. Re-assembles far enough to be able to start it up. Shorts data SDA and clock SCL at right moment on powerup with the point of a pair of tweezers....and gets in to BIOS....and resets password & loads defaults!
In the unlikely event of anyone else with one of these Thinkpad X121e laptops hits this problem - this is where the L08 security EEPROM is...and the pins I shorted.