HP Pro x360 435 G9 stuck in endless BIOS loop

[schiele]

After an attempt to deploy custom EFI keys to sign a dual-boot Linux installation for Secure Boot the BIOS startup procedure of the HP Pro x360 435 G9 went into an endless loop instead of booting anything. The loop always goes to display the HP logo together with the "protected by HP Wolf Security" logo, just to immediately turn off and automatically turn on again after a few seconds, just to start the loop again. Any attempt to enter the BIOS setup menu using the F10 key gets confirmed with an "Entering Setup Menu..." on the logo page but instead of asking for the setup password it just turns off in the very same way and restarts the loop.

I can still turn off the machine by pressing the power button for some time. But right after turning it on again, it is again stuck in the loop described.

Is there a way to force a factory reset of the Secure Boot configuration without being able to even enter the BIOS setup menu? Maybe there is some magic key combination to do so? Are there some other suggestions I could try?

[QuestPaul]

Hi, I have this same issue on 2 HP Pro Mini 400 G9s, they are getting repaired under warranty but the parts are delayed!

Did you ever find a fix yourself?

Thanks,