Thank you so much!!

Just a question, the BIOS now starts up in Manufacturing Program Mode with a counter, do I need to do anything else now?

Also - if it is useful for future reference...
After resoldering both chips, the laptop kept this screen flashing behaviour, however it only did so after the initial HP Wolf Security splash screen. It felt as if there was something hardware-related that intervened _after_ this very initial splash screen was passed.
I disconnected everything from the motherboard (keyboard, touchpad, etc.) and restarted it exclusively with...

Many thanks in advance for any help!

Motherboard: LANCIA13/Grizzly2.0-6050A3234201-MB-A01 (A1)
HP ProBook 635 Aero G8 (43A03EA#ABU)
S/N 5CG1345RXQ

Salvage laptop with lots of external damage, powered on OK but BIOS-locked.

I desoldered the back chip (a Winbond 25Q256JVEN) and read it twice using a CH341A programmer (same read).

Attempted to do the ActiveNvramRegn clear (there were three or four instances) and programmed on a brand new 25Q256JVEN left from another project (see below).

I was not expecting so many instances...

Hi everyone,

I'm new here, I'm a tinkerer with a background in mechanical and medical engineering and I'm keen to learn how to fix electronics and laptops in particular - as I lost more than a few over the years and it always feels like a shame!