Surface Pro 4 type cover suddenly not working.

I had the same exact problem described by everyone on a new replacement SP4 unit. Type Cover worked on the Windows 10 version that the device came with. After upgrading to Windows 10 version 1903, the Type Cover no longer worked. I tried everything from "Reset this PC" and all the Device Manager uninstall tricks, nothing worked.

SOLUTION (a mix of previous solutions):

1. Remove Type Cover (detach)
2. Uninstall keyboard drivers
3. Unplug charging cable
4. Drain the SP4 battery until it auto-shuts down (max brightness, stream YouTube 4K, etc.)
5. Make sure battery is fully drained by trying to turn it on again
6. Plug in charging cable and power on
7. MAGIC!!! (hopefully)

If the above doesn't work, try a combination of these two solutions from people who posted earlier (thanks Mike and Patrick for the tips):

Mike_K_9009 (page 29 of this thread at the bottom of the page)

1.       Shutdown Surface

2.       Detach Type Cover

3.       Detach Power Cable (Surface must run only on battery power for this fix but you do not need to have a full charge available)

4.       Startup Surface

5.       Adjust battery power settings to the following:

(this step is optional but if you do this, it won't take as long to run)

o   “Best Performance” Power Mode

o   Sleep: Never

o   Screen Turns Off: Never

6.     Run the Surface until the battery is exhausted and the Surface turns itself off.  (you can continue using the Surface or just let it run – playing a long movie will speed up the process)
7.     When the Surface battery seems exhausted, power up the Surface (do not attach the power cable or Type Cover yet).  You want to see the “dead battery” symbol on-screen before you do the next step.  The Surface will shut itself down if the battery is too low to start up - that's what you want for this step.

8.       Attach Type Cover

9.       Attach Power Cable

10.   Immediately after attaching the Power Cable, power up the Surface.  Do not let the Surface charge up before you power it on.  You may see the BIOS screen at startup but that is OK.  Just exit.

11.   Check for Type Cover operation.

12.   If Type Cover works, reset the energy profiles to original settings.

PatrickMbugua (page 19 of this thread at the center/middle of the page)

1. Switch off the computer.
2. Perform the two button restart i.e. hold the volume up and power button together for about 15 seconds.
3. The Surface UEFI screen will come up.  On the left side, there is a list. Go to devices.
4. A list of various devices allowed in your surface will be listed. At the bottom you should see type cover. Swipe the toggle button to the left to switch it off.
5. Choose exit and restart your surface.
6. Log in fully to your surface if you have log in credentials.
7. Shut down the surface.
8. Perform again the two button restart as described above.
9. From the surface UEFI screen go to the devices >type cover again and this time swipe the toggle button to the right to switch it on.
10. Choose exit and restart

I was offered an opportunity to purchase a refurbished unit for $450 and was not interested. You have confirmed that this was a problem created in an update. I would think that someone at Microsoft should be able to remedy this problem. It is very troubling that after purchasing many Microsoft products over the years, and being a long time Microsoft shareholder, there is no solution. This will inform my computer purchases in the future and my recommendations to others.

I don’t know why the location of the store is important. If you know of a fix for this problem that Microsoft initiated, or where I can go for assistance, please let me know. 

The location is important because other stores are not giving out this information. The statement "I was told that this was a known issue, that Microsoft had recently issued an update that rendered the keyboard inoperative and that there is currently no known resolution. " contradicts what others are told (they are told that these are individual hardware failures NOT caused by an update).

See:

https://answers.microsoft.com/en-us/surface/forum/surfaccesso-surfkeyboard/surface-pro-4-jul-2017-update-type-cover-not/1c188925-c234-4369-8c93-af74417534d1
and other threads

https://www.computerworld.com/article/3215225/microsoft-windows/surface-pro-4-type-cover-suddenly-stops-working.html Your only official solution is to spend $450US for an out of warranty refurb exchange. (Or use a Bluetooth keyboard)

Similarly - reports of SP3 typecovers not working began in August 2017. There is
a long thread at
https://answers.microsoft.com/en-us/surface/forum/surfpro3-surfperf/type-cover-not-working-but/059251f4-03f9-4070-8154-a8b8c9819c5f

• typically, even a wipe and reset won't fix these. Something seems to happen
  during the upgrade process (for any random update) that causes this condition.
  Sorry..

I don’t know why the location of the store is important. If you know of a fix for this problem that Microsoft initiated, or where I can go for assistance, please let me know.

I was told that this was a known issue, that Microsoft had recently issued an update that rendered the keyboard inoperative and that there is currently no known resolution. 

which Store told you this?