My Google Nexus 10, which quickly became my constant companion, started doing some really bizarre things about a month ago. The screen would go dark for no particular reason. It became more and more of a problem. When I’d try to unlock the screen, it would seem to work, but then the screen would go dark and I’d be right back at the lock screen.
Google was nice about it and replaced my tablet. But, once I’d configured the new tablet, the problem returned. This time it seemed even worse. I tried uninstalling any and all apps that had system privileges. That didn’t do it. I called Google twice more, but each time I called, we seemed to find a work around, like turning off the lock screen and extending the time-out period. But after I got off the phone, the problem would return.
I’d searched the Internet for people with similar problems, and hadn’t found any that matched. So it wasn’t a widespread problem. Google replaced the hardware, so it seemed unlikely it was the tablet itself. What did that leave?
Then I got to thinking about how the tablet turns the screen on and off when I close the cover of my “smart” case. A little investigation taught me that the “smart” case has a little magnet in the screen cover that winds up right next to the ambient light sensor, where the Nexus 10 has a magnetic sensor. It’s this sensor that detects the presence of the magnet and turns the screen off. When the magnet is removed, the unit comes alive again.
That gave me my answer. Because, when I don’t have the screen cover in place, it is wrapped around back, putting the magnet is close proximity to the magnetic sensor! Depending on how the cover shifts around while I’m holding the tablet, the screen goes off or on, depending on whether it detects the magnet or not.
It was a relief to figure out what the problem was. Now, all I have to do is make sure I keep the cover folded back in such a way that the magnet isn’t close to the sensor.
This whole problem could have been avoided, though. If you put a flat piece of steel or iron on one side of a magnet, it will block the magnetic field that would normally project in that direction. So it’s relatively easy to make a “one way” magnet. Had the tablet cover maker simply added that small piece of metal, I would never have had this problem.
I may fix it myself, by taping a small piece of metal in place on the outside of the screen cover, so when the cover is folded back, it will block the magnetic field from reaching the sensor. If that works, I might try altering the cover itself. If so, I’ll write up the results.