My HP split x2 keyboard has stopped working for a long time, but I didn't mind bc the screen was touch screen and detachable. Today, I turned on the tablet screen and I have a SMART Hard Disk Error and it is telling me to press F2 or Enter but my keyboard doesn't work.
You didnt say which Split model you have, but some models have a battery in the keyboard, some don't.
If you take the keyboard apart and find a battery, remove it, then reconnect the dock to the tablet. Usually the dock will start working again except it will drain the tablet battery faster.
As far as the Smart Hard Disk Error is concerned, F2 wil probably allow you to grab data off the drive if it will work long enough to do so. Otherwise, the drive will need to be replaced because its failing.
But they are not normal hard drives. It uses a Western Digital Hybrid Slim drive with a SFF-8784 SATA Express connector.
This is the only drive that I can find available on the web that would work...