To turn it off, reduce the brightness of the back light to 0 by hitting the F1 key repeatedly.
To turn it on, and increase illumination of back light hit the F2 key repeatedly.
I noticed this morning I couldn’t change the default search engine for Cortana. She loads Bing by default and I rather have Google or DuckDuckGo. I searched the internet for possible fixes and I came across a work around.
If you use the Chrome browser, you can download an extension called Chrometana. After installing the extension, Chrometana will ask you to select your default browser: Google, DuckDuckGo or Yahoo. Obviously, you don’t want Bing as your default because then you wouldn’t need this extension.
Now when I type in a search, Cortana loads Bing and Chrome quickly forwards the request to my search engine of choice. Based on my searches, it seems Microsoft has no plans to allow a change in the default browser, so I will take this workaround for now.
If your Surface Pro 3 keyboard will not work (touchpad and keys) then of course you try the obvious:
1. Make sure your computer has the latest Windows updates.
2. Gently clean off the connectors with a cloth and a small amount of rubbing alcohol.
But this evening, neither of these options worked. After rebooting several times, I went back to Google to search more possible fixes and discovered this one.
3. Make sure the Surface is turned off. Press and hold Volume Up (on the left side) and the Power button at the same time for at least 15 seconds. You may see the screen flash the Surface logo but continue to hold for 15 seconds. Release both buttons and wait 15 more seconds. Turn on the Surface as usual.
The third option above worked just fine for me this evening.