hp elite x2 g4 - how to get into bios without collaboration keyboard?

[mattger]

Hello all,
about 3 years ago I bought a HP Elite X2 G4. Now the keyboard (Collaboration Keyboard) is defective. Currently, this often costs several hundred euros as a replacement part here in Germany. Therefore, I bought a cheap Logitech Bluetooth keyboard. So far so good. On my laptop, the charging limit was set to 80% in the bios. Inexplicably, this setting has been lost. I suspect almost after a BIOS update? Actually, but no matter. Now, however, I can set this again in the BIOS, but I can no longer get in. That it does not work with a Bluetooth keyboard, was clear to me. But even with several USB keyboards it was not possible for me to call the Bios. You can see from the keyboard's LEDs that it only becomes active after the Windows logo has been visible for a few seconds. Too late to interrupt the boot and enter the Bios. Is it really not possible to enter the BIOS without the original keyboard? I don't buy a new keyboard for around 300€ when a new battery costs 50€.
Thanks for your help.

[mattger]

Nobody has an idea or the same problem?

[mattger]

Hello,
now I have taken the whole thing into my own hands and autopsied the keyboard. After I carefully pulled off the leather, I found that the flex cable is broken - exactly where the keyboard is bent when opening or closing.
My final question now would be, can anyone tell me which traces are responsible for the function of the keys?
The backlight and touchpad do not have to work.
Thank you very much.

By the way, it would be desirable if the life of the keyboard is longer than one year in the future. I for one will not buy a device (independent of HP) with a detachable keyboard. The Microsoft Surface Keyboard has exat the same problems.

Best regards
Matthias