It appears the USB keyboard functions properly once the system starts.
It appears the USB keyboard functions properly once the system starts.
Have you explored the bios settings? I recall certain bios include a toggle for USB power. That might be why it’s not working. You could also try updating the bios.
The laptop model I saw was the Satellite S870. I've already swapped out the CMOS battery.
It's possible that connecting via USB to PS2 and using a PS2 keyboard could work around the secure boot, similar to what's shown in the image. You might consider this option if there are no suitable replacements available.