OK, so everything worked out just fine, let me share my learnings from this:
1. HP 840 G5 more often that not seems to have password configured in the EC chip on the backside of the motherboard, in my case a Winbond 25Q128JV SMD chip.
2. This chip can't be read or programmed when connected to the motherboard, there seems to be a protection kicking in. Must be desoldered.
3. The chip can easily be read and programmed with CH341A programmer when desoldered, and RCUnlocker worked on the first try.
4. Beware to read more than once and compare readouts, also after programming,...

rddube[USER="84059"]rddube[/USER] I was hoping to not have to desolder the 16MB chip (since I successfully connected to the 32Mb using wires). Just to double check: How did you connect...

That is what led up to these questions, I suspect you are right, but in other replies in this thread it is clearly stated to be the 32Mb chip that should be patched (which seems impossible to me using RCUnlocker). Seems a bit inconsistent and would be interesting to understand if this is different in different versions of the 840 G5....

Hi everyone,
I have a HP 840 G5 that is admin password locked (abandoned from a company). I have been trying a good way to unlock it and reading up on almost the entire thread here it seems reading out the 32MB chip patching it with RCUnlocker is what most people say. I did this (was a Winbond 25Q256JVEQ chip) and to my surprise RCUnlocker told me that the 32MB file was not compatible and I should try a 16MB file. My two questions to anyone who could bring more insight:

1. Is RCUnlocker indeed not compatible with 32MB BIOS files? It seems a lot of people have run it successfully...