Yesterday I visited a local business to sort out a problem with their ‘cloud’ storage. While I was there someone who’d spent a long time trying to stop his Samsung Galaxy A5 from bleeping whenever he woke it up asked if I had any idea what might be causing the problem. When I asked for a demonstration, the phone didn’t beep. That was annoying as intermittent problems are much harder to diagnose than problems that occur constantly.
I said that I’d have to think about the problem for a while, but a couple of minutes later the phone beeped again. It seemed odd that the phone didn’t beep when its owner tried to demonstrate the problem, but started beeping again just minutes later when it was being used normally. I wondered if there was any difference between the demonstration and actual use, so I watched carefully as we went through the demonstration again.
The phone was in a wallet-style case, and when its owner was using it normally he always opened the case and folded the cover right back, i.e. 360 degrees, so it was completely out of the way. However, when he attempted to demonstrate the problem, the phone was flat on the desk and the case was only opened 180 degrees. At first it seemed ridiculous to think that this could make a difference, but then I noticed that the cover contained some business cards.
Further examination revealed a contactless credit card hidden among the business cards, and then the problem became clear. When the phone was being used normally, the contactless card was very near to the back of the phone and when the phone was woken up, the onboard NFC (Near Field Communication) facility connected to the card which caused the beep. When the case was only opened 180 degrees, the card was too far away from the back of the phone to connect.
This still didn’t stop the phone from beeping when it was woken up the way the owner normally did it, but as we knew it was the NFC facility causing the beep, we went into the phone’s settings and turned off NFC. He wasn’t using the phone for contactless payments, or for anything else that needed NFC, so switching NFC off wasn’t a problem.