Surface Pro 4 type cover suddenly not working.

Did you try the flipping of the surface pro without the rotation lock, and let it change its screen orientation, and then setting it back to landscape and see if the changes in orientation fixes the keyboard detection?

I hate to add another anecdotal experience that may or may not apply to others, but I'd been having this problem with my Type Cover on my Surface Pro 4 for months. Tonight, I did all available updates, including the 02/2020 cumulative updates, and restarted, still nothing. At that point, checking updates again, I saw a Windows 10 feature update to v1909, so I did that.

After restarting, my Type Cover came to life for the first time in months. O_O I was amazed.

I used it for a few minutes, then closed the Type Cover and let it suspend. Ever since, my Type Cover has been dead again. FML.

Interestingly, my KB is dead in UEFI, but the trackpad works. That hasn't changed. 

If whatever the Windows Update did can trigger it to work briefly, it sure seems likely this could be fixed by an update that addresses it specifically.

My keyboard works in UEFI/BIOS mode but not in Windows 10. Reinstalling drivers didn’t help. And I’m not about to restore windows because this is a software issue. damn near everyone has this issue from a software update. Microsoft **** man. 

I can verify that wiping the drive and re-installing Windows 10 has no effect on the keyboard issue. 

There are only two solutions that work reliably:

1. An external bluetooth keyboard (Not Microsoft)
2. An external USB keyboard

The other option is that if you take it to the Microsoft store, they will usually give you a credit toward a replacement unit.  In my case, I upgraded to a MSP7, which so far is working much better.

As a side note, the MSP4 had a number of performance / problem issues, which I originally attributed to it being a tablet-hybrid computer.  None of these issues appears in the MSP7.

This leads me to believe that the earlier versions were somehow more defective than previously thought, but still worked well enough to get them through their 3-year life-cycle.  (That is what Microsoft considers the life of the MSP).

My MSP7 is working very well, and the performance is much better.

My keyboard works in UEFI/BIOS mode but not in Windows 10. Reinstalling drivers didn’t help. And I’m not about to restore windows because this is a software issue. damn near everyone has this issue from a software update. Microsoft **** man.

And I spent $2,000 on this junk. Battery's dying like crazy. Rotation sensor is not working, and the type cover (and a 2nd newer one) is unusable.

Next I will cleanup everything on this devide and install a clean Wondows, let's see what happens - but I've lost hope.