Surface Pro 4 type cover suddenly not working.

Yes original Warranty still, I didn't buy it until much later after it came out. Maybe the model is also late to come out to NZ? So no magic phrase.

I would suggest others try a clean install of version 1903 May release of Win 10.

I have been making some posts previously about my keyboard issues and getting the SP4 replaced under warranty.

There was also someone posting wanting my case number etc? Not sure why. Anyway, yes I got a replacement, but it was dead on arrival and wouldn't power up.

use my keyboard on it. yay! However, its running 1703, so I will be spending the day updating it to 1903 and then give a further 24hrs before I consider it fixed. The reason is that my original one, I did reinstall 1803 on it, and the keyboard worked but slowly over 24hrs I went through all the issues I have experienced for the past few months before the keyboard wasn't recognised at all. I will update again soon.

Was your SP4 under warranty still? I think pretty much everyone else's in this thread will have long been out of warranty.  If you were able to get an out of warranty replacement, please share what the magic phrase was to get it done!

I have been making some posts previously about my keyboard issues and getting the SP4 replaced under warranty.

There was also someone posting wanting my case number etc? Not sure why. Anyway, yes I got a replacement, but it was dead on arrival and wouldn't power up.

use my keyboard on it. yay! However, its running 1703, so I will be spending the day updating it to 1903 and then give a further 24hrs before I consider it fixed. The reason is that my original one, I did reinstall 1803 on it, and the keyboard worked but slowly over 24hrs I went through all the issues I have experienced for the past few months before the keyboard wasn't recognised at all. I will update again soon.

I'm with everyone else with this problem and reloading the drivers didn't help (I do have the keyboard both in the device manager and in settings).  The other problem that happened with my keyboard going inop is that my hardwired (CAT5) connection disappeared.  I use my surface at my desk connected through a Tripp-Lite bar which gave me a hotter LAN connection than wireless but that's what disappeared.  I also take it with me but without a travel keyboard, it's kinda useless.  Having been in the business since MSDos 3.0 and retired for a couple, I get a kick out of the ways things get diagnosed and fixed.  My roots go back to vacuum tubes in military radios and the "split-half" method of troubleshooting has evolved to more like "wet it, wad it up, fling at the wall, and if it sticks, it's fixed."  If it were up to me this time, I'd format and scratch rebuild but, there are things out there that bite you if you don't know where to look and I don't need to get locked out.  We need to get a rational explanation of what's happened and then we can solve it but, that may not be forthcoming.

Unfortunately, that won't help those whose keyboards aren't being detected in the first place.   Without "Surface Type Cover Filter Device" in my Device Manager, Surface Type Cover won't appear in Devices and printers.   But this may still be great for those who can still at least see the keyboard.  Always great to have more things to try.