This worked perfectly. Thank you SO much for your help! It's my first time doing anything related to BIOS chips and I'm so glad there's a community of helpful people like yourself....

Hi all,
Thanks for your work on this.
I can't seem to get the patched BIOS to work.
I'm working on a Thinkpad T480.
S/N: PF1HZZPP (on sticker on case), System-unit S/N in BIOS is PF1LEPXM
Motherboard: NM-B501
BIOS Chip: Winbond 25Q128JVSQ

I selected the W25Q128JV chip type in AsProgrammer.
Downloaded the BIOS x 2, compared hash values and it was good.
Applied the patch.
After flashing the patched BIOS I just get the loud musical tune and a black screen. Never any words appearing.
Re-flashing the original BIOS makes it work...