A few days ago, after using my S5 for a over a year with no problems, I noticed that my battery was going down faster than normal and that my TV remote (TIVO) was very unreliable when the phone was in the same room. That made me suspicious so I looked at my phone using my digital camera. I found that the proximity sensor was on bright even though no call was in progress. (The camera can see UV light.) Once the light comes on when no call is in progress, it stays on until I reboot my phone. It stays on even when the screen is locked or off. The only way to turn off the proximity sensor light seems to be rebooting the phone. How can I find out what app or other process is turning it on when no call is in progress? Many thanks for any help.