HP 250 G8 | BIOS F53 downgrade issue

[FlorianZ]

Hi everyone,

whilst automating the installation of the F53 BIOS Update for the HP 250 G8 I have encountered a couple of issues. It occured to me that HP SSM could not package it correctly, which lead me to a manual installation attempt. While reading the .cva file for the update provided by HP at https://ftp.ext.hp.com/pub/softpaq/sp113501-114000/sp113998.cva I noticed something. It supports a silent installation with the parameter "-s" (started a cmd windows as admin + started "Insydeflash.exe" -s)!  So I tried that but it wouldn't work. 

My last resort was the manual installation, which I tried - and it did work. I finally upgraded from F52 to F53. 
But since I wasn't happy with the result I tried downgrading the BIOS from F53 to the next available step, which is F44A. I've tried just clicking through the setup, but the option to install it on the HP 250 G8 is greyed out.So naturally I grabbed an USB stick to create a rescue media, formatted it, started the setup again and  voila - I had a rescue USB stick. Or so I thought. 

I powered the machine off, (the USB was already plugged in), held down Windows + B while powering it back on but when it booted into the BIOS recovery screen it stated "BIOS recovery files cannot be found or the files are corrupted". After that I also tried clearing CMOS with holding down Windows + V whilst starting the machine, but it didn't do anything. 

My questions:

1. Is there a way to downgrade from F53?

2. Can I download F52 anywhere since HP only offers F53 + F44 and older?

3. How can I automate the installation of F53? 

Thank you in advance~