Lenovo T420 (Maximized)

T420 Hardware Maintenance Manual

The thinkpad T420 has only one SPI flash chip that hold the BIOS, ME, etc. It is located under the palm rest. Similarly to the T430, to access this chip complete disassembly is required. It is a straightforward process and takes approximately 30 minutes. For this follow the T430/x230 guide.

Here is the location of the chip. At some models the location of the dot where the red wire from programmer should go may be misleading. The dot you need is just black.

You should then follow through with configuring keys.