Right, some help needed from more knowledgeable members of the forum. This is my first time posting here, so my terminology may be off. 
T450 with a supervisor password. I follow the guidelines available on another reliable resource, erase the chip, apply the patched BIOS, remove the hard drive, power on the PC, and nothing. The power button remains illuminated, fan spins for the first 2-3 seconds, then stops. Nothing on the screen, no beeps or sounds. Hitting F1 yields no results.
Flashing the original dump back does not solve the issue.
I have tried CH341 own software, ASProgrammer and Colibri, BIOS file has been verified with no issues, which should rule out corruption when writing.
I have so far successfully patched two T440p using the same procedure, no issues at all.
Does anyone have any suggestions? Any help would be much appreciated.